real IP SBS 2003 server

Hi all,

I have windows SBS 2003 server deployed locally in my LAN network and working as domain controller I need to put real IP address from my ISP on this server to be able to access it from any ware, what is the most proper way to secure this server from outside? And if this will affect the local user to login for the domain to retrieve they resources? And it could be possible to have the 2 NIC one configured locally and the other one with real IP? I have trend micro office scan server installed on this server.
Thanks for the advise
Joseph.