Click on Applications and Gaming
The default tab selected is now Port Range Forward
In the first box, name your application. I'll use RDP (Remote Desktop Protocol) for my example.
Next, enter the start port of 3389
Since this is a single port, in the second box, enter 3389 again. So we're forwarding from 3389 through 3389 (only 1 port).
Next, choose the protocol from the drop down. In this case, it's TCP
Now, enter the last octet of the IP address to the computer on your LAN you wish to forward 3389 requests.
Place a check mark in the Enable box, hit Save Settings and you're done.