Ran into this on ehow just now, while looking at doing the same for linux with netcat:
"netsh interface portproxy add v4tov4 listenport=111 listenaddress=1.2.3.4 connectport=222 connectaddress=7.8.9.10"
Very handy if you want to push a certain kind of traffic from one network to another network (in my case I was looking at forwarding netflow traffic)
