Route rules advisement

Hi,

I have some trouble figure out how to make the following setup to work.
First of all, let me describe how my setup looks like.

Firewall: FreeBSD with PF filter
Outside: 217.xx.xx.xx/30, inside: 91.xx.xx.1/26, dmz: 10.0.42.100/27


VPN Router: Linksys with openWRT
Outside: 91.xx.xx.xx.2/26, Inside: 10.0.42.97/27, Tunnel: 10.0.19.0/16

Server: 91.xx.xx.3/26, FreeBSD

I what the server to access an specific ipaddress in the tunnel. And as
you can see the outside of the VPN router is connected to the inside of
my firewall. And the Inside of the VPN router is connected to DMZ on the
firewall.

The server is also connected to the inside of my firewall, but I just
can't figure out what routing rules I have to make, before the server
can reach the VPN tunnel.

Thanks in advance.

Best Regards,
Daniel.