What will cause column headings to change from letters to numbers in excel
2000?

We don't know. It is reported far too often to be just an incident. Most
people don't even know there is a choice!
But it's easy to correct:

ToolsOptionsGeneral, Uncheck "R1C1 reference style"

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Kind regards,

Niek Otten

Microsoft MVP - Excel

"Bob in Buffalo" <Bob in wrote in message
...
What will cause column headings to change from letters to numbers in excel
2000?

Most likely, in the course of clicking through various and sundry menus
you inadvertently selected "R1C1" reference style. If you'll click
Tools Options and select the General tab, de-select R1C1 Reference style and the column header will revert to alphas.

I accidentally encountered this very phenomenon- I received a sprdsht
from someone who had defined a named range as HR1. This resembles a
cell reference: is Excel toggling to R1C1 reference when such a named
range exists? If so that could be Bob in Buffalo's answer.