Thank you so much! What a relief! :)

"Dave Peterson" wrote:

Tools|Options|General Tab|Uncheck "R1C1 reference style"

This is determined by the first workbook you open in that excel session. So if
you happen to open a workbook that someone saved in R1C1 reference style as the
first workbook, you'll have to do it again.

zrossing wrote:

All of a sudden the columns in my Excel documents are labeled with numbers
rather than letters. It's making it confusing to do vlookups, etc.

Any suggestions for how this happened and how to undo it?

--

Dave Peterson