Windows Server 2003 offers WMI filtering for group policies. For example you can have a policy apply only to a specific model of laptop. Unfortunately you can only apply one WMI filter to each policy.

There is a tool called Scriptomatic which reveals all of the WMI classes, properties, and methods you need to use the WMI filtering capability.

For more information on WMI filters see page 759 of "Mastering Windows Server 2003".