Control playspeed by mouse position

Can anyone suggest some code which will use the mouse’s x-co-ordinate to determine playspeed- let’s say you have the mouse in the middle- for sake of argument, I have a movie 200px wide- at x=100- here speed=0. at x=0, speed=-1 so the timeline plays full speed backwards, and at x=200, speed=1 so the timeline plays full speed forward
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[FONT=Arial]The real problem is managing to change the timeline play speed.
So… any advice?:trout:[/FONT][/FONT]