Adding teamplay/deathmatch to Alien Swarm

[Welsh Mullet]

SInce i'm a little stuck on where to go with this, i decided to come here! :3
I'm working on part of an ASW mod, and am trying to create gamerules for a team dm style mode (first things first, get teams).

I wondered if anyone had had any experiance, as i have seen a few team asw mods.
Just some hints as to what to look at would be good. Code etc would be amazing

Thanks Lopers
Welsh~