Not out of the box.  There would need to be much customization, because you would probably need to go one of two routes, but in either case, you would probably want to disable the Admin features in the original portal. 

The first way would be to have two mirror instances of the DNN, and one is set up to only push our Admin updates to the other.  However, there would be much disparity in the cached data (pretty much everything edited as an admin). 

The other way would be to have two separate portals, but the new one has custom modules based on those available to admins that would edit the data of the original DNN instance.  You would suffer from the same disparity of cached values with this option as well.

I would certainly question the logic of wanting such an abstraction...  Your supervisors are likely reacting to a problem prematurely and instead of understanding and addressing the real issue(s).  They want someone to just take care of it for them. 

There really aren't any options for this, DNN isn't designed in this manner.  It would have to involve replicating the database and code.

Jeff