Good morning Jerry,
I dont test it, but maybe you can customize different authorization per Company with transaction: RSECAUT and restrict with authorization object: S_RS_AUTH
If really is not possible do the Company Code Restriction, maybe you need create a Z authorization object and assign the corresponding Authority-Check in the user-exit, etc. of the relationed program.
I dont sure if it is possible, I hope that you can restrict it.
Pleas eif you have any issue, please let us know.
Best regards.