You misunderstood what I posted. If you load RRAS on the DC, users will then connect to it EXTERNALLY (from home, hotel, etc). As soon as they do this, their computers, again, connected from an EXTERNAL location, will become nodes of your INTERNAL network, with an IP address assigned off the INTERNAL subnet.
They will then open RDP and type the INTERNAL IP of the TS to connect to it.
One more time, they are connected from EXTERNAL locations, over a VPN (PPTP or L2TP).
Is that clear now?
Cláudio Rodrigues
Microsoft MVP - Remote Desktop Services
Citrix CTP