Fighting game 'camera angle' position

I am making a fighting game and I have made an attempt to make a kinda moving camera effect. Bascially two movieclips are inside a container movieclip. When one movieclip moves back the container scales down ( zooming out ) and when the two movieclips are close together the container mc zooms in. The containers _x is inbetween the two movieclips.

This is the best iv tried to explain it - sorry its probably hard to understand what im doing. Here is my attempt at doing it but its not very good i was wondering if anybody has got a better way of doing it.