Here's something to try: Hack ProGrammer.
Here's how I'd do it:
Create a file to program a radio with TWO conventional channels in it. Each channel is at the band limit. Whatever it might be...
Save it, and now edit it to change the two channel frequencies by the absolute minimum increment possible. Save this one, too.
These codeplugs need to be as small, simple, and basic as possible. The difference between the two codeplugs will ONLY be the two frequencies in them. Otherwise, they should be IDENTICAL.
Using Hex Workshop, open both files and compare them carefully. They SHOULD be different only in the frequency data.
Once you've FOUND that frequency data, which I PRESUME will NOT be something easily readable like "921.00000", then at least you can refer to the version that is programmed with the actual band limits. Find those band limits you programmed into them, and
then using the limit frequencies AS DISPLAYED in Hex workshop, FIND THOSE DATA
STRINGS in various ProGrammer files.
These SHOULD be the band limits in ProGrammer.
Now, assuming you've FOUND the band limits in ProGrammer, edit them to match the
MODIFIED versions you put into the SECOND radio file you made. Save your changes
and start ProGrammer.
IF I'm right, and IF you did it right, your band limits will now have changed to be those
of the second file you set.
You're now about 80 percent of the way to your goal.
My belief is that Programmer handles frequency data as a hex offset from a reference
frequency. If you make a few experimental channel edits, you should be able to deduce
the arithmetic rules for frequency conversions. Once you do that, you should then be
able to program any arbitrary frequency limits you wish by making the appropriate edits
in ProGrammer where the band limits are stored.
Good luck. Try it and report back, please. I think I'll do the same.
Elroy