Touch avatar without animation permissions?

I would like to create a simple animation involving extending my arm and touching another avatar on the arm. Is there any way to script this by detecting the proximity of the avatar's body, without getting into synchronization, permissions, etc.? My guess is no, because the collision event is triggered by the bounding box of the avatar, not the avatar's visible surface, but before I give up, what do the experts say?

Well if you're clever, you could do it without permissions using sensors and animations as long as the object has its owners permissions. Infact, you ain't gotta be that clever, its not that hard, unless there's something I'm missing.

Sorry - what object? I'm talking about animating my avatar's hand so that it moves to a position in approximate contact with another avatar's arm. I could simply extend my arm and walk forward until I collide, but I'd like something a bit more natural than that.

I bought a 'handshake' animation in game (do a search for further info) that detected an avatar and presented me with a menu of avatars in the immediate area, which upon choosing a name.. would shake their hand... well almost.. lol.. you want to make sure you are facing them, otherwise it could be misconstruded what it is upto