Passing Routable IP from one NIC to the

my setup is 2 nic in an nt 4 server box, one nic is connected to the dsl router the 2nd nic is connected to the switch/hub. i have 5 routable ip addresses. is it possible to assign routable ip’s to the workstations behind the switch/hub? i’ve tried several settings but i could not make the clients get internet connectivity.