Rerouting incoming traffic to a dedicated machine on the LAN

Howto configure rerouting incoming outbound traffic to a Linux box on the LAN using port 22 of that Linux box ?
The network architecture is as follows :
ADSL router => Windows2000 DMZ (server) => switch : LAN

Somebody needs to connect to a Linux box socket 192.168.2.125 : 22. The router has a LAN address 192.168.1.1 The DMZ LAN interface has an IP address = 192.168.1.2 Its internal LAN interface uses 192.168.2.2
The target machine = 192.168.2.125:22