ipchains

[Kuokai Shyu <kkshyu manifold-engng com>]

Hi:

I have a question regarding the ipchains' rules.
I need to have a tcp/ip connection (port 5989) from an outside machine to
a server (192.168.2.200) on a specific port (5989) inside our LAN
behind a firewall. The firewall has an external interface (eth0) and
internal interface(eth1).

What input/output ipchains rule  should I append?
Do I have to open a port (5989) in the /etc/services?
And how do I do that?

Thanks in advances.

Kuokai