A permanent static route for Macintosh OS X (10.4.7)

I have set up OpenVPN on our pribvate network, but our special setup requires manually adding a static entry to the routing table of computers that we want to access from the outside via our VPN server. In SuSE Linux this is a nobrainer as Yast provides a section where to add static routing information. On MacOS X the command line works, but upon reboot the route is lost:

route add

Check what the route is for a specific IP:

route get

How to enable VPN clients to access LAN computers that are not running VPN software

I installed an OpenVPN service on our server. The default setup worked right out of the box. However, I wanted to use a VPN client to perform offsite backups of the computers in our LAN (using the backuppc software). First I installed OpenVPN clients on all of the LAN computers to be backed up, but OpenVPN on MacOS X seems to be a bit unreliable. Therefore I wanted to setup the VPN server to forward requests to our LAN network. The following changes were necessary: