Now set the route to send traffic through the tunnel. Just run this:
# /sbin/route add -net 192.168.0.0 gw vpn-internal.mycompany.com netmask 255.255.0.0
You should now be able to communicate with machines on the other side of the tunnel. Give it a try. If it doesn't work, try using ping and traceroute to figure out where your problem might be. If in fact it does work, move on to setting up scripts to do the work for you.