aenhancers

I´m trying to make an expression that starts a QT movie in 3d space when it´s distance to the camera is less than a certain value. I can of course set its inpoint when I want it to start, but I wonder if this is solvable with an expression.

I can make an expression to timeremapping with an if/else, that will trigger the movie when I´d like, but I´m unable to make it start from its first frame, it goes off at the current comp time...

Any ideas? Thanks!