Office 2007 Default Save type

We are being forced to start the roll out of Office 2007. We have over 250 users. We need to keep saving our files in 2000-2003 format due to other suppliers and branches not yet being ready to make the move. I know how to set the default save type (in the options), however I do not particularly want to go to every PC (particularly when some of the PC’s are in remote sites over 2 hours drive away) to change this setting.

Does anyone know of a registry hack or Group Policy that allows you to set the default save type for all apps in Office 07 to 2000-2003 format.

Thanks