Change frame rate on a QT movie without re-encoding?

Is there any way to adjust the playback frame rate of a QuickTime movie without re-encoding it? So, for example, if I were to have a movie that were 600 frames long and it's now playing at 23.976fps (making it ~25 seconds long), I would like it to play back those SAME 600 frames, but now at 29.97fps, making it only ~20 seconds long. Of course, my movie is a LOT longer, which is why I'm trying to figure out a way to tweak it instead of re-encoding the whole thing by running it through Shake or AE.

I've googled the heck out of this but I can't find a way to do it, aside from "add and scale" to an existing movie that's the right length, but as this is for broadcast output, I'm afraid that will not be accurate enough. Any other suggestions?

Mac Pro/Quad 3GHz/4GB RAM Mac OS X (10.4.8) QT Pro 7.1.3, Shake 4.1, AE 7