Not possible Channel Permissions ('invisible' room)

I'm assisting a new server admin in his server and I was requested to find out if there was a way to make a room visible to those with server admin powers only. A 'development' channel to speak of. Some place he could be and drag members to work without being visible to guest of other members, including the various 'mods' (those with basic channel editing powers).

Please pardon my newness to all this, I'm learning as I go :).

Not possible Channel Permissions ('invisible' room)