Yeah, you can get this working on your network dude. Your wireless network provides the network which can support any, with a few exceptions, ip network, just don't expect the machines to get access to the Internet if you do change it.
In the old days may networks used to run on a continuous coax cable, 10BaseT to nerds!, and this is a great way to think of your wireless network that your wirelsss router creates. So imagine that all your clients are on the same wire, including a router that routes you off to the Internet whose IP address is 192.168.1.1. Your Wireless network, just like this cable, can support machines on any IP address but if you do not use IPs from the 192.168.1.0/24 subnet they will not be able to see the rouer as the machines will be on a different logical subnet.
To play around with ad sites and services in a virtual environment you need 3 machines min.
VM1: domain controller, 192.168.1.100/24 default gateway 192.168.1.2
VM2: domain controller, 192.168.2.100/24 default gateway 192.168.2.2
VM3: Windows Server (Router) configure VM with 2 nics one on 192.168.1.2 and the other on 192.168.2.2.
To get Windows to route on VM3 just load up routing and remote access from the admin menu and then follow the wizard to turn it into a network router.
The nics on all VMs should be bridged and if so these VMs could be distrubuted accross multiple VM hosts. In fact VM1 could be on parallels, VM2 on Virtual PC, and VM3 on VMWare!