Yea, I can't think of any way either. Maybe if you put in a static route? (Advanced > Routing) from the 192.168.0.1 to your DHCP server over LAN? DHCP requests do go to your default gateway, I just don't know that would effect the PC's internet connections. Why do you need a router if have a device with a DHCP server? Why not just add a switch to the server and use that? Then connect the 4500 as a wireless AP?