While I don't understand your specific use case, the solution it appears you are trying to go for isn't recommended. Power Users, by design, went away as no user needs that much power. The Administrators account, which is always available, combined with UAC helps ensure that users that need admin level privileges get access. But few users should have this permission. The PU group historically had almost as much power as Admins and so was a security risk. It is like granting people admin rights without being able to use UAC to prevent malicious code from using it.
The recommended security approach is Least Privilege. Ideally a user never needs permissions to do privileged work in their normal account. Hence they are normal Users. If you really need to grant some users privileged access then the correct solution is to create one or more groups with the minimal privileges needed. For example you may need a set of users to muck with network settings so create a Network Manager group. Grant that group the minimal privileges to manage network stuff. Then add users to that group who need access. Do this for each set of privileges based upon user sets. Now you can grant users access to just the subset of permissions they need.
In the rare case where you need admin level privileges for a user then ideally have them log in to a special account rather than their regular account. If they rarely need that level of access then this prevents them from running, normally, with more privileges than they need.