Hmmm, seems they offer several types of VPN. If you are using OenVPN the default port is UDP 1194. There might be a different problem as well. OpenVPN can be configured to allow client-to-client connections, but usually isn't. Ask your provider. Also you may need seperate accounts for each PC. Again ask your provider.
We provide a peer-to-peer channel for customers that want to login to their home or office computer but I haven't seen much of that available on the Internet. You can get a 30 day free trial. You will need one for each PC (seperate emal addresses).