I am making a spreadsheet where I need to prevent people from entering
anything other than a number in a particular cell. (The entire
worksheet will be locked except for a single, critical cell. This cell
can only contain numbers.)  How do I lock out any character other than
0-9?  If locking out is impossible, can I construct an IF statement to
provide an error message?

I currently have a cell next to it meant to catch numbers higher than
90, and that cell's formula is:
=IF(B7>90,"Contributions over 90 minutes are negotiable.","")

Perhaps there is some way of saying "If B7=(everything other than
0-9),"Numbers only please."

Hello jhabley-ga,

I believe the feature that you are looking for is called Data
Validation (under "Data" on the Excel menu).  I've only used it once
or twice, so I'm not qualified to give you a full answer.

Good luck.

Googlenut

Thanks googlenut, I'll try to track it down at my end then. :)