SRV 2008 W exchange in VMware WS

Well, setting up a image for SRV 2008 & trying to install exchange 2007. added the role for AD Domain Services. how should i deal with dcpromo & the issue of naming the domain... since it is a test lab and i do not need to control a domain so when entering something like test.lab23.com or any non registered real domain will produce errors down the line with the dns servers.

any help will help, thx