Time for some extremely rough ASCII art.
|------| /LAN_B ME ->|ROUTER|->LAN_A-> -LAN_C |------| \LAN_D
LAN_A is a server with the necessary exposed port(s) to connect to. Basically, I'm wondering if there's any way for me to connect, from outside of my LAN, to LAN_A, and through it, connect to any of the other computers on my LAN as if I were actually on the LAN (RDP, FTP, any service, really - as if I were actually on the LAN). Sorry if this seems like an ambiguous explanation, but I basically just want it to be as if I were really on the LAN and for each other computer on the LAN to have their own IP address that I can send or receive connections to.
My router is running dd-wrt, so if I could actually just connect to my router, that would be great, too.