Public accessable network (hotspot kinda)

I have a network that is open to the public via wifi and hardwired connectivity. the only service running on the network is DHCP from a windows 2003 server (also acting as router). I am looking for a solution that will force all new clients to a Terms & Consent page when they try to access the web via the network.
I have looked at proxy solutions. however, i do not see how to configure the scenario I am looking for. either i am missing something or looking in the wrong direction. any help would be appreciated.