How about just using John Walkenbach's addin:

http://j-walk.com/ss/excel/files/supersub.htm

(Macros that run while you're editting a cell won't do anything useful.)

John wrote:

I would like to create a custom button in XL2k to format the selected
text as subscript, superscript, etc. It would function just like the
built-in buttons in Word. That is, I could select a portion of the
text in a cell's string, hit the button and the selected portion would
be formatted. As is, when I select a portion of the string the macro
menu options are greyed out. I note that the copy and paste buttons
don't grey out. Has anyone found a work around?

Thanks,
John

--

Dave Peterson