If I understand correctly, what they want is to refer to cameras by hostname instead of by IP in the VMS? So instead of having 192.168.1.89 you'd have lobbycam.myco.com.
From what you describe, I'm also assuming you have DHCP running on your network and everything gets dynamic IP, there are no static IP's? (other than your router of course, and maybe a couple of internal servers).
The part that confuses me, is that if your IT manager is so specific about this, he should be able to troubleshoot basic camera settings with you to make this work as desired. If your DHCP/DNS server is setup correctly (example tutorial: Howto setup DHCP Server and Dynamic DNS with BIND in Debian | Debian Admin ) then as long as each camera has a unique hostname, when it requests an IP address, your DNS servers zones should be automatically updated.
If that's not happening, it might be because the cameras have no hostname configured, or because something is wrong on the IT side.