Hmm... don't see why it wouldn't be possible... What a neat idea--but not really. Security risk. I think it's possible already with ipkg, maybe.
Most people just use port triggering though.
Trigger Ports 6667:6677?
A guide said to use 6660:7000 but if you use torrents perhaps you see the risk
Incoming 113
TCP
You may need to expand that port range