How to access RemoteApp from RD Gateway Services 2012??? Need help with the setup.

Hi there,

Just wondering if someone can shed some lights here.

A lot of the articles out there shows you how to install RDS Gateway but it doesn't tell how do user use it.  Through the RDWeb? Through the MSTSC RDP?

Here are my setup:

Internal Domain:  ABC.LOCAL

RDSWebGate01.ABC.LOCAL (IP: 192.168.1.2) - Web Access, Gateway
RDSBroker01.ABC.LOCAL  (IP: 192.168.1.3) - Connection Broker
RDSHost01.ABC.LOCAL    (IP: 192.168.1.4) - RDSH Hosts

Wildcard certificate  (*.XYZ.COM)  Loaded and trusted.

External IP Address :  Y.Y.Y.Y
Internal IP Address :  192.168.1.X

Everything works fine internally..    https://RDSBroker01.ABC.LOCAL/RDWEB.

I want to extend the RDWEB to the internet so that users can use the RemoteApp from home computers.

So this is what I thought I should setup and it should work... 

   ------>     Firewall   ---->   RDSWebGate01.ABC.LOCAL   --->  RDSBroker01.ABC.LOCAL  --->  RDSHost01.ABC.LOCAL 
   Y.Y.Y.Y      NAT                      192.168.1.2                                192.168.1.3                              192.168.1.4
   (Ext IP)    HTTPS 443
                   UDP 3391

I have External Routable IP Address Y.Y.Y.Y points to RDGWEB.XYZ.COM which will get NATed to the RDSWebGate01.ABC.LOCAL
I setup the RDS Gateway Services through the Deployment Overview.

So, by right When I browse externally through URL  htpps://RDSWEB.XYZ.COM/RDWEB, I should get my RemoteApp login page. Which I did...  Cool.  All good, when I login, I see all those published Apps.  All Good...  This is where I get confused.  When I click on the published app, let say notepad.exe.  I was not able to launch the app.  I get error messages like the following:

Is that how people setup the GW in the infrastructure?  What is wrong here?

Any help would be appreciated.