We have created some RealJukebox files ourselves, and experimented with this. Renaming the .rmj files to .ra or .rm DOES work using Switch, but the issue is that the decoding of the file takes as long as the audio file is. For example, if the audio is 5 mins. long, the Switch decoder will take 5 mins to decode it. This problem is not caused by Switch itself, but rather is a problem with the .rmj format.
I suggest you do not use RealJukebox anyway to extract audio from audio cds, use our Express Rip product instead:
www.nch.com.au/rip
you can save to mp3 directly, which of course will save you a lot of hassle.