OpenVPN bridged + client with lan behind

[ieracos]

Hi, it here is my status:
- A server with a lan (10.8.6.0) and with ip 10.8.6.1; this machine is behind a NAT (we will call it CN);
- A server with a public ip and no lans (we will call it S);
- Some other clients that will eventually join the VPN (we will call them Cs);

My goals is:
- Build a bridged VPN (with S as server and CN as client) that extends the lan 10.8.6.0 (all eventual Cs will get a 10.8.6.x address);

Just to make things clear, if CN wouldn't been behind a NAT, I would use it as the server making a standard bridged configuration.

[ieracos]

No one can help me with this? :S