FreeBSD ipsec and NAT

[Simon Taylor]

Hi All,
I currently have setup a site to site vpn using racoon on my freebsd
firewall. All is well there and I can connect through the vpn when I am
on the firewall and get the connection fine.
Now I want to be able to connect from other machines through the
firewall - this is where I come unstuck, the ipsec policy allows for my
external address range to connect through the vpn, but then I would like
my internal addresses to first get translated and then routed through
the tunnel. But instead when I connect with my internal addresses they
get translated, but then try and use the conventional gateway on the
machine instead of picking up the ipsec policy.
If that makes sense... I am using FreeBSD, ipf, ipnat and racoon.
Any help appreciated 
Simon