hmm wat you've sad i totally get except for one thing :P
You might try looking under any advanced routing options, im not sure but i think its PVC routing settings or policies, you can define a IP or IP range and/or port range within the IP(s) that is outside of the LAN and should a attempt to contact/connect to that IP be made from within the LAN, that the IP your attempting to contact well be altered to some other IP you can set,
see i have no idea wat PVC is, lol, i looked it up really dont get that, but of course i went to find it on my router and computerrr, but i have no idea wat im looking for lol, see i just got the router from my ISP and they didn't give a manual or everything, dumasses, so can ya like push me where PVC settings r, i didn't see them on my router settings..
