Mecanim hand/arm look at target (Aim), not pro?

I'm making a simple multiplayer game. I have a hand and gun that only the player can see and a outside mesh everyone else can see. I want my hand and arm of that outside mesh look at my (first person view only) target next to the gun. I can't find a way to do this so far. I've seen the mecanim tutorial. He gets the head to look at a ball. that's basically what I want, but I want it for the arm. The mecanim official tut doesn't even say how the head is selected (chosen through script) to do this. I was looking at IK and it seems even if I figured it out that its only for pro. So is there a easy way to get what I want through unity free? That is my mesh arm which is mecanim to look at a certain target? Thanks.