Not sure whether Elements 7.0 just can’t do it as suggested might be the case, but one thing worth checking before giving up if you’re not sure:
Make sure there is that there is not a mismatch of Mono/stereo between the Group and the audio track you want to record it to. In other words, if the Group is stereo, a mono audio track might not see it as a potential input. Has slowed me down late at night more than once!