You might also try AllChars or something similar.
Doh! Looking at their documentation made me realize I am using a Gateway 2000 fully programmable keyboard. I can program my a-e-i-o-u-y and n keys to have the desired effects just by making macros for alt-a, alt-e etc. to substitute the alt-0225 alt-0233 etc. ascii codes.
There's still one problem unsolved, though. The code for the upside-down question mark requires a code of alt-00BF, and the "F" instead of sending the ascii code opens up the File menu (i.e., alt-F) in Excel. (I tried to put that in here and the "B" part of it opened up a bookmark menu!)
Ah! I know a workaround. Use the Insert Symbol to get that upside down question mark into the Windows clipboard and paste it whenever I need it. That'll work until I forget and stick something else in the clipboard, but if I have it saved to an unused cell somewhere on the spreadsheet it'll be easy enough to clip again.
¿Will that work? Yep! Now, what is the code for that upside down exclamation point? Got it.
á é í ó ú ý ñ ¿ ¡ Ready to go now. Thank you.
tanstaafl.