Moving an object in script....

How can I do it? The problem is, I need a object to move back and forth through a wall. I can do this with and animation, but with an animation, the collision box stay in the same place; and I need it to move along with the object. So that when the object is in front of the wall, the players bolt can collide with it, and when its behind the wall, it cannot.


Thanks,

Lane