Greg,
At it's most granular level you can only load-balance on an L2 port-channel using the following:
Awesome Catalyst Switch(config)#port-channel load-balance ?
dst-ip Dst IP Addr
dst-mac Dst Mac Addr
dst-port Dst TCP/UDP Port
src-dst-ip Src XOR Dst IP Addr
src-dst-mac Src XOR Dst Mac Addr
src-dst-port Src-Dst TCP/UDP Port
src-ip Src IP Addr
src-mac Src Mac Addr
src-port Src TCP/UDP Port
This will not get you "this port to that port" loading but might get you a better spread across the channel depending upon the type traffic that is being sent. What your talking about would require PBR (Policy based routing) which, as far as I know, is not there for any L2 policy decisions that would meet your needs.
Hope this helps you,
Don