Function ColumnLetter(ColumnNumber As Integer) As String
If ColumnNumber > 26 Then
' 1st character: Subtract 1 to map the characters to 0-25,
' but you don't have to remap back to 1-26
' after the 'Int' operation since columns
' 1-26 have no prefix letter
' 2nd character: Subtract 1 to map the characters to 0-25,
' but then must remap back to 1-26 after
' the 'Mod' operation by adding 1 back in
' (included in the '65')
ColumnLetter = Chr(Int((ColumnNumber - 1) / 26) + 64) & _
Chr(((ColumnNumber - 1) Mod 26) + 65)
Else
' Columns A-Z
ColumnLetter = Chr(ColumnNumber + 64)
End If
End Function