Monthly Archives: April 2017

#Excel Worksheet UDF that Adds a Comment to Any Cell by David Hager

There was a lot of interest in my post on modifying a shape with a worksheet UDF.

The original idea was posted in 2007. I seem to remember, though, that the use of a UDF to modify cells occurred before that time. The initial discovery was that a UDF could add a cell comment to ANY cell. I can’t find the original reference, but this technique was last documented at:

I have modified the the UDF shown in that article to add a timestamp feature.

Function AddComment(rng As Range, str As String) As String

If Not rng.Comment Is Nothing Then rng.Comment.Delete

TimeStamp = Date & ” ” & Time

If Len(str) Then rng.AddComment.Text str & ” ” & TimeStamp

rng.Comment.Visible = True

End Function

In the example workbook, I entered the AddComment function in cell D6, but the range argument can point to any cell. In fact “range formulas” can also be used.

The INDEX, OFFSET and INDIRECT Excel functions all return ranges, so any formulas built with these functions can be used in a UDF where a range argument is required. The following example uses the INDEX function.

=AddComment(INDEX(NumRange,MATCH(MAX(NumRange),NumRange,0)),”MAX value in NumRange”)

where NumRange is defined as =OFFSET(A$1,,,COUNTA($A:$A),) ‘auto-expanding range

In this example, the formula INDEX(NumRange,MATCH(MAX(NumRange),NumRange,0)) returns the range of the cell containing the max value of NumRange, and as such it can be used in the first argument of the UDF. So, as numbers are added to column A as shown in the figure


the function will add a timestamped comment to any cell in that range that is the max value.

Obviously, there are numerous and more complex examples that can be built using this technique. I hope that you will find this useful in your projects.

The example file can be downloaded here.


Excel Short & Sweet Tip #7(Highlighting External Links) by David Hager

Using conditional formatting to highlight external links has been used before

but it required a VBA solution. Now, with Excel’s new FORMULATEXT function, it can be accomplished using only Excel formulas. So, using the following formula defined as IsExternalLink


Conditional formatting will highlight the cells containing “[“, which is associated with external link formulas. But, a more robust formula can also be used, as shown below.




#Excel: Using Conditional Formatting to Highlight 3D Formulas with Defined Names by David Hager

There was a comment on LinkedIn about my post about using CF to highlight 3D formulas

“Since I never use a direct reference (or, come to that, enter a formula without naming the range to which it applies) any 3D reference I might use would pass under the radar. Unless, of course, you have an array UDF which will parse the formula to yield a set of references; in which case can I put in an order?”

Initially, I replied that it was not possible. But, the challenge was irresistable. I started working on the problem and, after a number of dead-ends, I was able to come up with a solution. It required a VBA function to return an array of defined names.

Function DefinedNameArray() As Variant


Dim Arr As Variant

nCount = ActiveWorkbook.Names.Count

ReDim Arr(1 To nCount)

For N = 1 To nCount

cPos = InStr(1, ActiveWorkbook.Names(N).RefersTo, “:”)

ePos = InStr(1, ActiveWorkbook.Names(N).RefersTo, “!”)

If cPos < ePos Then

Arr(N) = ActiveWorkbook.Names(N).Name


Arr(N) = “”

End If



DefinedNameArray = Arr

End Function

What the VBA function does is return an array of defined names, but only places the items meeting the correct criteria for a 3D formula in the final array (which is the same concept using in the initial article).

In this case, the InStr function was used to locate the positions of the first colon and exclamation point in the RefersTo string and the values are compared. If cPos<ePos, then the name is added to the array and a null string added otherwise. This array is used in the following formula to find if a 3D defined name is part of the string returned by the FORMULATEXT function. It was defined for use as a CF formatting formula, as shown below (F5 was the active cell when defined).



Both F5 and F7 contain formulas using 3D defined ranges.

Peter, thanks for the challenge!

You can download the example file here.


Excel Short & Sweet Tip #6 (Shuffling a String) by David Hager

The ability to randomly scramble a string using Excel formulas does not appear to be possible without helper cells. So, a VBA procedure is needed to accomplish this.

Originally posted at:

this VBA function procedure uses a string as the argument and shuffles that string. Copy/paste this procedure into a module in the VBE.

Function ShuffleString(s As Variant)

On Error Resume Next

Dim CL As New Collection


ShuffleString = “”

Do Until CL.Count = Len(s)

R = Int(1 + Rnd * Len(s))

CL.Add R, CStr(R)


For i = 1 To CL.Count

ShuffleString = ShuffleString & Mid(s, CL(i), 1)


End Function

So, the string in A1 is rearranged with =ShuffleString(A1) entered on the worksheet. For example, the string “evert” is shuffled to “rteve”.

#Excel: Using Conditional Formatting to Highlight Cells Containing Native 3D Formulas by David Hager

Conditional formatting (CF) in Excel can be used to hightlight cells that meet certain criteria. In this case, I wanted to create a CF that would highlight cells containing formulas that use Excel’s native 3D references. So, this would be like the following example.


So, I tried to determine what was unique this type of formula string compared to others. What I noticed was that the first colon in this formula always comes before the exclamation point. Thus, I started working on a solution on that basis.

Note, though, that there are ways to write a formula containing a 3D reference that will not meet this criteria, such as:


So, don’t use those kinds of formulas. 😊

To lookup the position of the colon in the formula string, the following formula is needed.


where F6 contains the formula.

The corresponding formula for looking up the position of the exclamation point is:


By comparing the two formulas, the following Boolean expression wrapped in an IFERROR function is defined as Is3D:


Applying this formula as a CF on cell F6, you can see that F6 is highlighted as expected.


You can download the example file here.


Excel Short & Sweet Tip #5 (Hiding Error Triangles) by David Hager

Would you like a way to remove those green error checking triangles from worksheet cells, yet retain error checking? Go to File, Options, Formulas, Error Checking. Leave the “Enable background error checking” box checked, and change the Indicate errors using the color (default is green) to white. Of course, this only works if the cells are white. To turn off the error checking and the green triangles, change the “Enable background error checking” box to unchecked.