The only way I have found to do this is with a second router and a switch or hub (any inexpensive NAT router will work). The problem is that even if you get the P334 to forward requests to the modem, the modem doesnt have a route to get them back.
Assign the modem an IP address on a different subnet such as 192.168.10.1. Disable the DHCP server in the second router. Assign the second router a non-conflicting LAN IP address such as 192.168.1.2 mask 255.255.255.0. Assign the second router a WAN IP address of 192.168.10.2 mask 255.255.255.0 gateway 192.168.10.1. Connect the modem and the WAN ports of both routers to the switch or hub. In a command window at the PC enter ROUTE ADD 192.168.10.0 MASK 255.255.255.0 192.168.1.2 Or ROUTE p ADD 192.168.10.0 MASK 255.255.255.0 192.168.1.2 To make the route persistent
Now you should be able to open 192.168.10.1 in a browser window. -- Jim Anderson