RDGW 2012 in Workgroup and DMZ supported?

Hello Forum,

Iam testing with a server 2012 RDGW server in our DMZ to forward RDP-Packets in our internal LAN. The Server is not a member of our Domain. Iam able to establish connections from the internet to our LAN-Machines, but have to deal with local groups and users on the RDGW.

My questions: Is that a supported scenario in Server 2012? I will not make the RDGW a member of our Domain because of the security risks an all the open ports into our LAN.

And if it is supported, how is it possible to connect it to a scenario based installed RDP-Environment in Windows Server 2012?

Thanks in advance

FAndreas