IDM in SCIF environment and integrated DNS.

I am looking to test IDM in a SCIF type scenario as a proof of concept for a centralized authentication solution for one of our government customers. Since it is a closed network I will install with the integrated DNS option. However, I need to test this in our corporate network lab that already has an external DNS.

If I still set this up with the integrated DNS, am I correct I can assign it a seperate domain such as .IDM.company.com and not have it interfere with the corporate DNS?

Thanks
Robert