Office NAS and ntwork drive from home

[trek103]

I would like to use a NAS so remote users "think" they are on the Intranet. Specifically, the NAS is part of a workplace network which is linked to the Internet. External users (home workers) with access to the Internet should see the NAS as if they were sitting in the office intranet. What is the best setup for that? So for example Windows users should see a network drive in the office and the same drive when working at home and loggin onto the NAS via their home router-internet connection.