Well, you could leverage the existing council system to cover this. It's one of the reasons it got left in despite the majority response to the poll indicating it should have been removed.
Councils can have commands assigned to them that only that council can use. So it seems like it would fit what you want, at least partially. What it ultimately sounds like you want is a new set of command flags along the lines of:
Admin, Builder, Coder, Quest, Enforcers, etc.... and so forth. This wouldn't be overly difficult to setup. Commands could be flagged as one group, flagged for multiple groups, or not flagged at all. A perfect example is the CMD_GHOST flag which will eventually be used to allow commands being used by PC's who are ghosts. Any command not flagged as such is rejected.