I don't use the registration queue myself.
But I believe you need to give them control panel access.
Control Panel » Group Management
select the cp link to the right of global moderator
Not sure which option to pick but try the
Can edit users
Just place a 1 in the field.
I just tried this in version 7.5.6
It does not work even with full cp access.
The only way is to make them a admin.
Last edited by Ruben; 06/03/2011 5:21 PM. Reason: added update