Routing in a little LAN

I'm newbie, so be indulgent please ;-)

I have a little LAN, with 3 PC connected to an adsl router 3com812. (A
Suse 8.0, a W2K and a XP). In the W2K box there is running Emule,
while in Linux I intend to run Edonkey. 'Help' of emule says that I
must forward ports it uses (5 ports, I think) through the router to
the W2K box. This will force me to select different ports for Emule
(and also forward they), and things can became more and more complex
if other similar applications intent to run in the third box. The
question is, is that the correct approach to the problem? I
must say that the IPs are static, with NAT enable in the router.

Regards,
Toni
(Sorry about my English).