What exactly do you mean by 'detect a hit'?
If you are manually moving stuff around then you will need to do your own collision detection, either by detecting when the entity is with a certain distance of another (or the terrain) or by using ray casting before the movement.
If you want the physics engine to detect the collisions for you then you will have to move the entity using the PushObject command .
Been there, done that, got all the T-Shirts!
