web server with multiple websites, only showing one??

Hi all, 

I have a very basic setup with my XG125 firewall. 

In a nut shell, I have a Windows / IIS web server with two web sites, both web sites are sub domains. 

- testPortal1.website.com

- testAPI2.website.com

- Default website (disabled)

if I point the default web site to either of the two sites, it loads fine externally.. 

if I disable the default, it would appear that the XG isn't forwarding the subdomain to IIS to correctly resolve. so no web pages are shown.

So far, I don't have a dedicated firewall rule for this (thou i feel one coming), i just have the "web server" specified to my DMZ box.

Does anyone know if there is a "how to" guide that would assist me in this scenario? or just a case of allowing 443 to the DMZ from external.

also, I would like to lock down external access to testAPI2.website.com to a handful of IP addresses that I can specify. so I'm guessing I need two firewall rules, one for each web site.

Thanks in advance

Dave