As we await some kind of Avid PC solution for audio, here's something you can do in a pinch:
After much trial and error, I found a freeware program that is able to read the 32-bit audio file within the r3d QuickTime proxies. Avid won't accept the 32-bit audio files. And it's difficult finding a program that will convert the 32-bit audio to a wav file that Avid will accept.
There's a great little freeware program called Front End Convert Drop from K-werkx Inc. I downloaded it from www.download.com. Anyhow, you can actually drag an r3d QT proxy directly onto this little application and then choose to convert the file to Wave audio. And voila, you can now import the audio into Avid. I'm sure there are more pro-audio solutions that will do the trick, but this one is free and the only one I could find that would actually read the 32-bit Big Endian file within the proxy and convert it (realplayer pro might do it, because it seemed to play the file, but I wasn't going to pay $35 to upgrade that crappy software from the non-pro version).
At least there's a PC solution for exporting audio that you can manually synch in a PC Avid to the video you've exported from RedCine.