Audio from 3ivx .mov

[Reedbeta]

I have a Quicktime .mov encoded with 3ivx. There are 4 audio tracks and I want to extract one of them. I have the 3ivx codecs installed, and the file plays perfectly in WMP. But neither Avisynth nor GraphEdit will render the audio! Any ideas how I can get the audio out of this file?

[setarip]

Use QuickTime Pro...

[Reedbeta]

I will try to get a copy of it, but is there any other way that might work?

WMP can render the audio, so there must be some way to get it working through DirectShow.