I'm sorry, but I don't quite understand your question.
If you mean that 'example.com' is reachable only via vpn, then simply connect vpn from client to server.
If you don't have a dns-server locally then edit /etc/hosts on client (=local machine). The entries looks like:
Code:
192.168.0.1 www.example.com example.com
If that's not what you asked about, then please return with details.