Jay,
Having done this myself over 20 years ago I can easily see why it's important, but its been so long that I can't remember where I stored the floppy disks that have my program on them. Even if I did there's probably a 50/50 chance that they're unreadable after all these years.
At the risk of reinventing the wheel this thread contains a wealth of info on the general means for sending commands to TMCC, and Legacy, units (ignore the fact that the title focuses on the word "Arduino"):
https://ogrforum.ogaugerr.com/...57#77875232662193957
You'll note within it that there are a number of different software programs and utilities referenced. One of these may already be available from a forum member, or other source, to do what you want. If not, the detail found in the thread should point you in the correct direction to write your own.
Keep us up to date on what you find.
Mike
