If you use static IP addresses for RRAS clients, it's basically a same approach as if you'd use static IP addresses for the computers in your LAN.
When the client has connected to your local network through VPN, the client behaves more or less the same as your other LAN clients. You should configure the VPN client Network Interface Card (NIC) DNS servers / WINS server just like you'd configure the computers on your LAN. If the VPN client will have the internal DNS server configured, then the VPN client will be able to resolve internal DNS names through this internal DNS. If the client will be configured with the external DNS, the DNS queries from VPN client will traverse through VPN, through your LAN network, through your LAN gateway to your ISP DNS server.
FQDN is a Fully Qualified Domain Name - i.e. microsoft.com. <-- note the dot at the end. I.e.: 'cat.animal.com.' is FQDN, 'cat.animal' is not a FQDN, nor is 'cat'. From what I've encountered so far, Windows Server 2003 configuration files sometimes skip the trailing dot in FQDN.