I'm not doing a good job of explaining the roundy shot from my previous post so I'll try it again.
Two rooms opposing on opposite sides at the end of a hallway. Opening frame is on an actor walking toward camera from the other side of the room we're looking into. Camera is just inside the room with the dolly itself in the hallway. As the actor approaches, dolly pulls back about four feet (that's really all you have) and as he passes camera, and crosses the hall, the dolly roundy's around, basically executing a pan with the actor as he passes. He stops in the doorway of the room across from the one he started in. Camera ends up 180 degrees from where it started over the actor's shoulder.
There, I hope that clears up the confusion. If it doesn't, let me know and I'll try it again.