Change SameTime server name in Notes 7 and 8 client silently - how to?

HiWe have 250+ users connecting to one SameTime server (ST1) version 7.5.1. Clients are 7.0.1 and 7.0.2 and are moving to 8.0.2. We are now moving to a new domain and new certifier.

I have created a new Sametime server (ST2) release 8.0.1. I can reset users and connect to the ST2. It works.

How do I change all users to point to the new Sametime server, without having to re-configure all Notes Clients?

I have created an explicite policy writing “ST2” in SameTime server name in desktop policy. By looking at the field “SameTimeserver” in local address book I can see “ST2” is registered. But restarting a client and connecting the SameTime I can see it points to the old server.

I can reset the user and point to the new server - but I would rather not do this 250 times.

Ideas?