Zend certified PHP/Magento developer

OpenVPN Port Forwarding

I have an Ubuntu server running an OpenVPN access server and want to redirect traffic from a certain port to a windows machine connected to the vpn. IE: A server is running on my windows machine @ port 8000, I want all incoming traffic to the access server on port 8000 to be sent to the windows machine in the WAN. How might I go about doing this?