That's similar to what I wanted but not quite there. I don't really like the direct mapping to groups from LDAP although thank you for pointing it out. Problem is I need multiple OU containers joining one group. I think I'll just get a list of all users from our AD admin and make a flat file database to enrol people on the appropriate course for the time being, until I can get proper database integration with our systems.
Keep on Moodling!