How many vpn connections with SBS2000

Hi,
I will be installing Small Business Server 2000 on a server using the new Intel S845WDI-E and a router switch. I want to set it up at one location and have two seperate Doctors office share this server. I would like to connect from two other offices simultaneously and let the Doctors share this server. In other words, two seperate doctor practices from three offices connecting using vpn and sharing this server can it be done?
Thanks