Climbing

I'm in the process of making a climbing game but i'm stuck on the climbing part. I have the arms(Placeholder). You can bring them up individually but i want to be able to grab onto thing and move up or down them. Please Help!

 

You are going to need to create hand holding points , which have colliders on them, probably triggers

http://docs.unity3d.com/ScriptReference/Collider.OnTriggerEnter.html

You will also need colliders on your hands. Or raycast from the camera . So either you move the hand until it hits the hand hold , or you look at the hand hold and move the hand there if its close enough.