Ok, so I've got a standard DSL internet connection, with the modem having a web GUI that is only accessible by it's public IP from "inside" the DSL network side. I have a VPN tunnel up from HQ to the office. I would like to setup NAT so that I can hit that DSL modem web GUI from behind my VPN connection. For this example's sake, let's state the following:

- DSL public network is 1.2.3.0/24

- My VPN router (831) is at 1.2.3.1/24 on the outside

- My VPN router (831) is at 10.0.0.1/24 on the inside

- My HQ network is is available to that office on 192.168.0.0/24

GOAL: Machines on 192.168.0.0/24 can reach 10.0.0.0/24 just fine. I'd like to setup a "NAT" or "static pipe" or something to allow machines on 192.168.0.0/24 to reach 1.2.3.1 from the VPN tunnel side by specifying a destination of say 10.0.0.50, and having that NAT or translate somehow into 1.2.3.1.

Hope this is making sense to somemone. Thanks in advance.