I can't wait to find time to look here. I have an
Excel sheet which controls my ham radios via the serial port. Found
the I/O routines in a Ham Yahoo group and spent considerable time
(several questions here too) honing the rather weak code that came with
them.

I used it to learn VBA and research the command sets of several
radios. I now have one sheet which not only sends commands to one of
radios, but also sends speech commands to a text-to-speech module, all
with one serial port (the radio and module commands are reasonably
orthogonal - with a little help). If I can make the time, my goal is
to write code in a PIC chip for a small device that allows better
access for blind hams.

If you or anyone wants to see it I can send the latest version that I
have here @work. It might not be the prettiest code, but it's
reasonablely robust (compared to what I started with) and chock full of
comments and Debug.Print progress feedback.