iptables abilities

[Sven Burgener <sburgener@xxxxxxxxx>]

Hello

I'm looking for a way to connect two parties (computers) that both have 
a private IP address.

         (Internet)       (Internet)
     A <------------> X <------------> B

A: 192.168.1.13
B: 192.168.1.99
X: public IP address

In other words, can iptables act as a "relay" between two computers 
which both have a private IP address?

Cheers
Sven