first thing to do is make sure that your pc has a fixed IP adres.Therefor open your network connection and look at the current IP adres, gateway, dns ... you just need to copie the same numbers in the TCP IP V4 protocol of your network.
Once that is done and the pc is still able to connect to the internet you need to log on to your router.
There you need the page with "portforwarding".
Here you enter the IP adres (that you made fixed just before) and as port you need to enter "86" (this is the standart port for this software).