Add route exceptions to a VPN with network manager

[Erwan David <erwan@rail.eu.org>]

Hi,

I use a vpn with network manager which routes everything through it.
I'd like to add some exceptions for local or not so local ressources 
that cannot be reached through the VPN.
The ideal situation would be to be able to give as gateway for those 
routes "the defayukt gateway before the VPN was up".
Is there a way to do this ?

Thank you