The Agilent MS 5977, 5975 do not technically use DHCP for getting an IP address from the network, but BOOTP. BOOTP is similar to DHCP (it's the great grandfather of DHCP) and unfortunatly you will have to setup and manage a BOOT server to do this. I'd say it's probably not worth the work. There is a BOOTP server on the chemstation 1701 series software disk you can use.
The easist way to manage the IP address is for the Network to administrator to manually assign you an ipaddress and they you can use the front panel of the MS to type it in.