[Openswan Users] vpn with nat

[Ghido]

hi all i have two network, one in usa and one in italy connect to 
internet by a adsl router with a pubblic ip, but this pubblic ip are 
natted to my local ip address:

10.0.0.0/24
lan-italy-------a.b.c.d-----openswan1-----internet---e.f.g.h

10.0.1.0/24
lan_usa-------l.m.n.o------openswan2----internet---p.q.r.s

i read some online how-to but i don't connect two networks. can someone 
help me?

Thank's

Ghido