If you can assign DNS to each device manually, just use the DNS server on your router, network, or use something like OpenDNS.
I don't know how to configure your DHCP server to send the correct DNS server.  Perhaps try assigning it to the router's DNS server instead.  It may be possible that the building's DNS server is a part of a different subnet which can't be (or not configured to be) routed from addresses behind your router, so using the router's DNS should work, as should something like OpenDNS.