quick question on 12.3(13)BC capabilities

Hi all,
I'm not expert in cisco router so my last few days spent on reading
the IOS documentation led to nothing (mainly since I'm having
difficulty defining my search...) Anyway, I have a small question for
you experts before I commit to a more detailed (and expensive) expert
answer.
Is there a simple way to configure a CMTS router supporting version
12.3(13)BC and above to route according to layer 4 information. Can I,
for example, route a certain src.ip/src.port to a certain router port
and all the rest traffic to another?
Thanks
Alex