Before a port can be forwarded, the pc needs to have a static IP.

There is a basic version on static-IP setup below here or follow the next few links:

1. Follow this guide to Setup a static IP on your PC. Portforward.com
2. After setting up the static IP you can forward any port to that PC in the network. Portforward router guides

This are the basics for setting up a Static IP

A static IP address is useful for hosting servers.

Get your currect IP info.

1. Click Start Menu >
2. type: CMD
3. press enter on the keyboard
4. Type: ipconfig /all
5. Now you can see your current PC network info

To set a static IP address in Windows 7, 8, and 10:

1. Click Start Menu > Control Panel > Network and Sharing Center or Network and Internet > Network and Sharing Center.
2. Click Change adapter settings.
3. Right-click on Wi-Fi or Local Area Connection.
4. Click Properties.
5. Select Internet Protocol Version 4 (TCP/IPv4).
6. Click Properties.
7. Select Use the following IP address.
8. Enter the IP address, Subnet mask, Default gateway, and DNS server.
9. Click OK.
10. Reboot PC
11. Your computer should now displays a static IP address.