This feature is available in the RDPlus Enterprise Edition.
It will allow you to access any of RDPlus servers in your farm, using only one access point which will be your Gateway Portal Server.
Since this server is going to be accessed remotely, you will need to set up one port redirection rule on your router, including the http or https ports depending on your preference (80 being the default port for http and 443 for https).
Click on the Gateway tile then click on the “Reverse-Proxy Server Role” tile:
Once you completed your list of servers, click on “Save Gateway Reverse-Proxy settings” and restart the Web services located in the Admin Tool’s Web tile.
You can generate a Connection Client which will connect to an Application Server through the Reverse-Proxy Server.
To do so, assuming that your gateway has public IP 184.108.40.206 and your backend server has internal name “srv2”, then use the special URL 220.127.116.11:443/~~srv2 in the server address field of the Connection Client Generator.