I have no idea whether that model supports UPnP, but by the sounds of it, it does not. Port forwarding sounds like the way to go. But yes, you WILL need to set up a static ip FIRST. Otherwise the process simply won't work at all. To set up a static ip, see
PortForward.com - Free Help Setting up Your Router or Firewall. Then for port forwarding see
Port Forwarding for the Dlink DI-804V. Remember, a static ip MUST be done first, otherwise the port forward rules will be useless & should be deleted. Port forwarding is based on ip number so if it's dynamic, it simply will not work after it changes. It's best to do a separate port forward for each of TCP & UDP. But it's ok if you click for both options in the one port forwarding.