Can I access files on the LAN Drive over a VPN (Virtual Private Network)?
Yes, this should be easily achieved. The LAN Drive will appear on you LAN just like any other machine, and if you can access your current PCs on this LAN then you should be able to access the LAN Drive. One issue may be the use of CIFS/SMB for file sharing, as this may not work over your VPN (depends if it forwards netbios broadcasts) if not then you can still use FTP to access the LAN Drive.