Transparent mode Block DHCP

[Asher100]

Her, so I need to have two dhcp servers on my network one on the WAN side and one on the internal side, I have a forgiate 80C in transparent mode, and I'm getting DHCP assigned addresses on the internal side, I've tried changing the "broadcast-forwarding" to disable on the internal port but it complains about something to do with IPSec, (sorry, I'm not with the fortigate at the moment won't be for a couple of days over the weekend) and won't save the setting. Anyway thanks. BTW I'm doing this because we don't want Internet access on the internal but we do on the external, but we want to share a Windows server (files sharing, VOIP, etc.) between the two, would the DMZ port be able to share the server between the two without the DHCP server (running on the Windows server) handing out addresses to the clients on the WAN port (Then I have the perfect solution).