Chip Pearson posted this solution to the newsgroups for finding the column letters when you know the column numbers:
Function ColLetter(ColNumber As Integer) As String
ColLetter = Left(Cells(1, ColNumber).Address(False, False), _
1 - (ColNumber > 26))
Very smart function, in my opinion. Sometime before the year 3,000, Microsoft will hopefully increase the number of columns in Excel (Hey, I can dream can’t I). The challenge before you is to write a function that converts a column number to its letter equivalent assuming columns go to ZZZZ. That’s about 450,000 columns – maybe more than I need.
I was just going to whip up a short function to do this and post it, but after 10 minutes I still couldn’t do it. Rather than admit defeat, I turned this post into a challenge for you. It’s Friday, you weren’t going to work anyway, were you?