Configuring Shared folder always Offline.

We are using clients running Win XP into an AD domain and try to use
Offline Files feature for laptop.

I wonder if the is a way to configure the default behavior for a
designated shared folder to be always offline (even if the network
connexion is up).
We just want to enable users to sync their cache on demand and never try
to write data on the remote server. Of course, this should not applied
to All Shared connected to the client.
I tried the csccmd /disconnect for the specific share, it works, but I'm
looking for a persistent feature with AD or registry.

Thanks