Connecting to intranet site

Hi i want to connect by Intranet Web site to some other Bureaus in some other part of the country.
My intranet site supports IIS and can be only accessed by employees in headquarters , now i need to extend all this service to all regional office keeping common database.
I could have published everything on INTERNET , but that wasn't tooo secured and can't run replication in Database for maintaining same bit of information on both the servers i.e locally as well as on Internet.
I mean can i keep my database locally and give the access to run the Application from any local IIS.

could VPN be a better solution?? if yea pls tell me how to go for it??? ,

Thanks
Jazz