Adding A Specific Type Of Group - Permissons

I have a handful of users being added to your company's domain from Switzerland. They need to be able to access our Sequel Server via a VPN connection to our primary domain controller but i don't want them to be able to access any other servers(or there shares) on the network. (there defaulted to be able to use any of the network shares via the domain user group which is primary on all network users)

A little guidance on where to start would be appreciated, thanks.