The closest thing I've seen is an addin from John Walkenbach:
http://j-walk.com/ss/excel/files/supersub.htm

Fupp83 wrote:

I know i can put text in a superscript by formatting the cell, but i was
wondering if there was a button that I could put in the toolbars to do the
same thing. I know word has the button but i could not find it in the
toolbar customize section. Could this be downloaded or is there a hot key
that does the same thing? Thanks for the help.

--

Dave Peterson