Microsoft ForeFront TMG setup Https web server

I am trying to setup a HTTPs IIS web server. The web server has a private IP （internal ip）, say, 10.255.30.41. I am not quite familiar with this web security issue. I google a lot, and successfully setup it.

I make the self-signed certificate use the makecert tool. create the CAroot.crt and server.crt etc. everything goes well,when I configure the web server and IIS. I mean that I can access my website using https://10.255.30.41 in my company just for internal access. now I want to publish the website to internet, but my company uses Microsoft ForeFront TMG for security purpose and the web Administrator doesn't know how to configure it. I googled a article about TMG publish https web： Publish secure (HTTPS) Web Site with TMG 2010 the guide uses a domain name for the website, but I don't have a domain name I just have a public IP that TMG use mapping to my internal IP.

I followed the guide configure the TMG, but it doesn't work. anyone ever do the configuration I met. and any suggestions are appreciated.Thanks.