Nat between subnets

[disa]

Dear,
I have a pfsense 2.0RC1 successfully running.
I have openvpn server working, when I connect I get an IP like 172.20.0.0/24
I also have a bridge interface with subnet 192.168.4.0/24
I push the 192.168.4.0/24 to the vpn client, and they can ping the pfsense on it's 192.168.4.x ip
But when the vpn client pings another hosts on that subnet they receive the ping from the 172.20.0.x address and they don't know how to reply (pfsense can't be the gw of that subnet)
I'd like to be able to masquerade my ip in 172.20.0.0/24 to something on the 192.168.4.0/24 subnet when it tries to reach that subnet. Is this possible? How?

thanks

[GruensFroeschli]

Create a static route on the gateway of this subnet pointing to the pfSense for this subnet.
This is the easiest way.

If you really really really want to do source NAT (i don't recommend it), assign the OpenVPN interface, enable manual outbound NAT rule generation, and create a rule for the OpenVPN interface.

[disa]

Ok I'll try to go with the outbound rule, thanks