(racoon 899) [ROADWARRIOR] detect remote ip for firewall rules insertion...

hello,
 
i have set up a security gateway with a 2.6.10 kernel, ipsec-tools 0.3.3, racoon and iptables.
 
i use a script which bring ipsec tunnel up and insert related firewall rules, but with roadwarrior configuration i cant insert firewall rules because i dont know remote ip...
 
is there any clean solution for detecting remote tunnel ip when it comes up in order to insert firewall rules ?
 
thx in advance for your help.