Configure plan for admin use only

Is there a way to configure a plan that can be used by the admin to register others.
If the plan is hidden from everyone but super users and the super user has to log in to see the plan you will of course get
Error
You are already logged in

Thanks,

You'll have to set "Visible for Access Level" under the Access tab as needed, login, then use the Subscription tab on a users profile on the users behalf. The alternative is to make it a backend only plan with "Allow access from site frontend" parameter under the Access tab of your plan.

I must be missing something. Tried your first suggestion...
On the Access tab I have:
Allow new subscriptions Yes
Allow access from site frontend Yes
Changed visible for access to Super Users
Allow access from site frontend to Super Users

Result in the frontend is that this plan shows as an option as if it is Public.
If I log in as an admin super user, and go to the registration screen...I get
Error
You are already logged in

If I go to the user list and choose a member with this plan already
I see initially the members subscription. If I go to edit...the subscription tab is missing...

Hope you can straighten me out.

You're trying to view the registration page, you can't if you're logged in. You need to go to the users profile page and subscribe them to the plan using their Subscriptions tab. There is no subscription tab in profile edit, it's in profile view. If it's not there ensure it's public and published within CB > Tab Management. If still not there ensure you didn't disable it within CBSubs > Settings > Display > Plans.