Using VPN with Netware 4.1

How do we specify an IP address for the gateway on a Novell 4.1 server? We have a VPN connection between two remote locations and we can’t ping the novell server from clients at the remote location, but we can ping the NT server. Basically, we have a corporate office with two servers (Novell & NT) and we want remote workstations to have access to the corporate office servers. We are using Netopia routers for the VPN connection.