Basically, vpn to your office is made to "make you feel you are on your office network". Logically you are connected to your office network, but physically you are not connected directly to your office network.
Windows only can call hostname or cname each other if :
1. The PC is connected to the network physically.
2. The network have WINS server to manage netbios name on the network
https://technet.microsoft.com/pt-pt/lib ... s.10).aspx
(please correct me if I got it wrong
)
To put it simply if you want to call your server only by hostname via vpn you have to :
1. Configure your own WINS server properly on your office
2. Point your WINS server on ppp profile setting
Otherwise you can point your dns to the office router and add static dns using fqdn format so you can access file sharing or remote desktop using fqdn server name.