You don't say which version of the program you're using, but in version 9 you can use Share/Computer/Audio to output your audio.
I use Steve's method all of the time, and edit the Audio output in Adobe Audition. You will want to Export/Share to PCM/WAV @ 48KHz 16-bit, and keep that format both going and coming back into PrE. Remember that you will be working with an Audio file, that is the full (or almost) Duration of the Timeline. When you Import that edited Audio file, give the program a few moments to Conform that newly Imported PCM/WAV for editing. I suggest not touching the computer, until Conforming has completed 100%, and the little progress bar in the lower-right of the GUI has disappeared. If the Imported Audio file is short, and your computer is fast, you might not even see that progress bar, but the Conforming has taken place, just the same.
I like to keep the original Audio on its Audio Track(s), and just use Window>Audio Mixer to Mute that/those Track(s), leaving only my edited Audio on its own Track un-Muted. This is a "fail-safe," just in case I change my mind along the way, and wish to revert to the original Audio for some reason. It is much easier to Mute-Unmute, than to gather up all of that original Audio again.
Good luck, and happy editing,