automating DNS entry

Hi does any one know how to automate or is a registry key that i can add to login script that would enable me to change the DNS entry of a pc.Cause currently our very good colleuges in HongKong will de deploying their new DNS server that they wanted us to us.Unfortunately we are not using DHCP server’s cause we bill the user for the trafic that was generated by his own ip adrs.
any suggestion will be gadly appreciated

Thanks
Warren