User blog comment:DaNASCAT/Technical Update: August 23, 2011/@comment-3080486-20110826124900/@comment-3388044-20110826125409

I wonder if, in the MediaWiki namespace, you were to create a page called  MediaWiki:Grouppage-sysop  and input SP-Staff, if that might work?

Alternatively, use the diagnositic tools that came with your browser and find out what element it is that feeds Admin into the masthead. Then, you might be able to use CSS to re-label it.