Pulley rope winch animation

Hi every one

I m working on a project where i have to animate a rope running over a pulley something as shown in the link below .

http://www.youtube.com/watch?v=M9F9Gwf5hGw&feature=related

Could someone explain the methodology used to do this .

It would also be of great help if somebody could forward me a CAD assembly of any asembly having a pulley and rope in it

Thanks and regards

Rahul Sankapal

SolidworksMotion Studies