I have a project need to replication those data from different location to the headquater office ( sales amount and inventory information )

I want to use MSDE in every site and use MSSQL 7.0 in the headquater office.

is there any tools for Visual Foxpro to call the computer to dial up to the internet? and then how to make those site to replication the data to the headquater ?

I only know that in LAN is workable but I don't know how to do it thought internet.
DO I need to form a VPN in order I can work it thought internet ?