[Openswan Users] advanced routing? ipsec l2tp

[foren titze]

hello,

i habe set up an ipsec/l2tp tunnel between windows an linux with help of jacco 
de leeuw.

now i connect my windows roadwarrior to the linux server and get a correct lan 
ip from the inner side of the gateway. e.g. 192.168.121.251

now i would like to connect from the roadwarrior over putty to an computer 
behind the gateway. the topology is like:

roadwarrior====vpn_gate---INTERNET---firewall---computer(213.x.x.x, extern ip)

so from the roadwarrior over the vpn_gate to an computer in the internet, 
which can only accessed with an ip of the inner lan, e.g. 192.168.121.x/24. 
all other world wide ip's are droped.

but, when i try to connet to this computer, i arrive with the extern ip of the 
vpn_gate.

how can i masquerade or route it? thanks for help!!!