You simply need to create a Port Forwarding "Service" in the modem for your game. When in the Port Forwarding section of your modem, next to where the drop-down box is for the services list, choose "Create." From there, simply name the service, probably the name of your game, make sure Port Forwarding is selected if it absolutely requires forwarded ports. Then, choose the Protocol (TCP or UDP) needed for the game, and for Global PortStart and Global PortEnd, fill in the port range you mentioned above. Base HostPort should be the lowest digit port that needs to be forwarded.
If you need to add an additional Protocol besides the firstly created TCP or UDP rule, simply click "Add" while in the Service creation page and fill in the required information. Once this is done, click Save and then you'll be taken back to the Port Forwarding screen. Choose your new service from the drop-down list (will be at the bottom), choose Host and then either pick the PC with the game on it from the drop-down list or enter in it's IP address.
To access your modem's Port Forwarding section, visit
http://192.168.1.1/ and go to Firewall Settings > Port Forwarding. Be aware that if the modem's firewall is set to High, Port Forwarding will not work. In addition, if you are prompted for a Username and password, try admin/password, admin/password1, admin/admin, or admin/admin1, or even your Verizon Username and Password.
