Remote desktop thru firewall via vpn
So... simple with ssh-tunnels:

Into the terminal:

ssh -N -p 22 -c 3des user@firewall.example.com -L 15900/10.1.1.1/5900 -L 13283/10.1.1.1/3283


Where:

user@firewall.example.com - is an valid username on the firewall, and
10.1.1.1 - is the address of the lion-server on the internal network


This will create two tunnels between local computer and remote firewall.
In the Remote Desktop.app you should manually add the remote server like this:



Now, you can observe/control the "internal-server" via tunnels thru firewall.example.com.