There is a hack available that you can redirect a user to a certain place once they have registered. Yet this is for vB2. You will not find vB3 hacks here until the release of RC1.
So until then, try over at
www.vbulletin.nl as that is where hacks for GAMMA are.
Note you must make more than 2 posts there and then wait an hour before you can download anything over at that site.