Redirect to port 22 on linux PC.

[DragonRider7]

I have an outside developer doing some time studies here. They have installed a Linux system that they need to remotely administer. I need to know if there is a way in ISA 2000, to open a port above 8000 for all traffic and redirect that to port 22 on their linux PC.
(They have set up their linux system to listen on port 22 for incoming SSH connections at which point they will a VPN over the encrypted port 22 connection.)

Thanks
Mike Bennett