iptables - port forwarding in LAN

[Snehasis Sinha <ssinha@connectivasystems.com>]

Hi,

I am trying to port forward in a closed (not connected to real internet or outside network) network (LAN) to a machine; but could not do it successfully. the senerio is:

I have a host_a (10.5.1.100), host_b (10.5.1.200) and host_c (10.5.1.150) connected among themselves. from host_c i am accessing http service at host_a using http://10.5.1.100:80. I can access tomcat server using http://10.5.1.200:8080, from host_c. now I want to use http://10.5.1.100:80 to access 10.5.1.200:8080 from the same host (host_c), ie. all http requests targetted to 10.5.1.100:80 should be redirected to 10.5.1.200:8080, so that pages from host_b:8080 comes to host_c but appear to come from host_a:80

how to do that using iptables. please advise.
thanks in advance

-snehasis