PtP Question

I'm very new to routing and networking:


Client has a remote office 3 miles away from where I've arrainged a DSL connection. Client needs to be able to access their Cisco router equipment remotely via public IP. My Force 200 PtP bridge will be between the DSL connection and the office. Is it possible to "move" the issued public IP address downstream to thier office router? Can I use a standard 192X address on the PtP bridge? I know it will work if their equipment is colo'd at the DSL connection, however, I'd like to leave their equipment in their office. Perhaps I just put a milrotik at the head end and give them a VPN into it. Any advice or insight appreciated.