The first post in this thread has a list of extensions. Most of the extension developers focus on a particular ruleset. 5E being the biggest one. Unfortunately, unless someone has come up with a universal extension that does those things, you probably won't find one for RMC.
Not sure what you are trying to accomplish.
According to
this post, you can use the Base Spell Attack table, and it will bring up the RR table. I just tried it and it does work. It first brings up the BAR Table, then you apply that, and you get the RR table.
https://i.imgur.com/0I8L3dU.png