Port forwarding

[localhost@xxxxxxxxxxxxxxxxx]

Good day.

I would like to find some information on what the best way to forward IP
would be. This is how the system should work. I have 1x 2.2.14 linux box,
and 1x NT4 (sp4) on a network, and the linux box is the gateway and
firewall with 2 network cards eth0 192.168.0.1 eth1 216.4.160.150, which
has alias eth1:0 216.4.160.148. now im trying to forward ftp connections
to the NT box, on 192.168.0.10, the http/www is working fine with a
program called datapipe. But if i try datapipe an ftp connection it
connects, but when the ftp client issues the port command it just stops,
so you can't do a "ls" from a windows system, although a unix ftp client
sort of works. 

I have tried different places on the net, and they all
assume that the system will only have 2 networkcards and no virtual hosts
running, this linux box has Apache running on 216.4.160.150, and if you
connect to the virtual host eth1:0 on 216.4.160.148 you get the NT's
iis. I would apprecate any help. 

Thanx 
Gareth Gregor.