Custom NPC's?

I know how to model, rig, animate, all that. I’ve done custom AI for other engines. Does anyone know where I would start with getting my own NPC working in-game and functioning?

You can script one with .lua or code one into a separate mod using c++ using the Alien Swarm SDK or the Source SDK “Create a Mod”

I’d plan on doing a mod for something Half Life related, I knew it involved some C++, could you point me out where I’d start? I’m have a very small experience in programming however I’m willing to learn.

The VDC has some good articles