IIS setup a web site to be accessed without a domain name....how?

I want to setup a web site for testing without a domain name.
I have 3 web sites with domain name that are working fine.
I am working on a web site for Millhouse and they already have an existing web site with the domain name millhouse.org.au

I want to setup their new web site on my web server for testing purposes and so member of the organisation can view it (as http) to assess it.
I want to be able access it like this:  58.168.225.214:8080
But what I have done so far isn't working:

I have setup port fording in my modem with WAN and LAN ports of 8080.

And 8080 as the port in the web site settings in IIS.