You can access the CS filesystem shares from a computer on the self managed network or while connected to the VPN. To mount a file system, go to the Finder and from the Go menu select Connect to Server "Finder>Go>Connect to Server". In the dialog box, enter the server address:
smb://files.brown.edu
or to go directly to your user folder, enter:
smb://files.brown.edu/cs-home/<username>