I think so but it's not a great solution. You could use the front and rear speaker jacks, then map the rear speakers on top of the front ones using virtual speaker.
Two things to consider are that they might not be exactly the same output (but probably close enough for most), and the SQ from the rear jacks isn't as good as the front ones (they use different op amps etc. and have worse specs, but again probably not noticeably).