Hi. I'm not sure what to call this or what it's referred to as, but what I'm trying to do is use Windows Access Manager to connect to my ISP from a PC that is connected to a DI-524 Wifi router which is in-turn connected (through the WAN port) to my ADSL Modem.

However, the only way to make this actually work is to instead connect the modem to one of the LAN ports rather than the WAN port.

I need this to work through the WAN so that the other computers are still protected by the router's firewall, and all but one PC connect without having to use Windows Access Manager. (and without taking up all the LAN ports)

Right now, everything works up until the point when i try to connect with Access Manager. I can browse the internet just fine, but I need JUST 1 PC to connect with Access Manager for the purpose of that PC having its own IP address to connect to (it is for a web server)

Any help would be greatly appreciated!
Thanks in advance