You can assign a Global Group to the Power Users group using the Restricted
Groups policy setting.
Just follow the steps outlined in 320065 with the following exceptions where
Windows XP workstations are used to configure the policy.
- For Step 8 you will need to click the Locations button and select the
local machine name.
- For Step 10, after you click Browse, you will need to click the "Object
Types..." button and place a check next to Groups.
NOTE: Use of Restricted Groups does not append to existing users or groups
already listed in the Power Users group, it overwrites them. So, if any
users or groups already exist in the Power Users group you will want to make
sure and add them in Step 11 as well.
FYI: The Power Users group is not a valid group on DCs. Don't set Power
Users in a Restricted Group at a level that will apply to the DCs because
the DC may see Power Users as a SID (unresolved name) and policies may fail
to apply to the DCs.
320065 How to Configure a Global Group to Be a Member of the Administrators
http://support.microsoft.com/?id=320065