Hi Larry
WinGate VPN will allow your remote users to connect to the LAN safely and securely through a VPN tunnel and acts just as if your LAN has been extended to include the remote users that join (so these remote users will be able to share files, browse directories etc just like on a normal LAN).
In your case the WinGate VPN is installed on the Server and then you will need to install WinGate VPN on the remote machine that will be connecting to the server from each location.
Usually the server at head office will be configured as the host machine, and a small configuration file can be exported (saved and emailed usually) to the remote machines. After installing the config file(as simple double click) the remote machine will have the required info to connect to the host.
Depending on your licences and setup, machine participation in the VPN can vary depending on your needs. For an overview and more detail on WinGate VPN take a read of our Vpn whitepaper
http://www.wingate.com/resources.php
Hope this helps
Erwin