Function to convert column number to letter?

Question

Does anyone have an Excel VBA function which can return the column letter(s) from a number?

For example, entering 100 should return CV.

Answer 1

So I'm late to the party here, but I want to contribute another answer that no one else has addressed yet that doesn't involve arrays. You can do it with simple string manipulation.

Function ColLetter(Col_Index As Long) As String

    Dim ColumnLetter As String

    'Prevent errors; if you get back a number when expecting a letter, 
    '    you know you did something wrong.
    If Col_Index <= 0 Or Col_Index >= 16384 Then
        ColLetter = 0
        Exit Function
    End If

    ColumnLetter = ThisWorkbook.Sheets(1).Cells(1, Col_Index).Address     'Address in $A$1 format
    ColumnLetter = Mid(ColumnLetter, 2, InStr(2, ColumnLetter, "$") - 2)  'Extracts just the letter

    ColLetter = ColumnLetter
End Sub

After you have the input in the format $A$1, use the Mid function, start at position 2 to account for the first $, then you find where the second $ appears in the string using InStr, and then subtract 2 off to account for that starting position.

This gives you the benefit of being adaptable for the whole range of possible columns. Therefore, ColLetter(1) gives back "A", and ColLetter(16384) gives back "XFD", which is the last possible column for my Excel version.