How do we "hide" the "workflow configuration" menu from the html page

We are creating a new responsibility for one of our clients, so that their users can re-assign workflow notifications and set up vacation rules for other users.  I have managed to create a responsibility that just has the "Administration" html screen with the Vacation Rules submenu, and the Notifications submenu, but the "Workflow Configuration" submenu is showing, and I also want to remove this from the responsibility.  Is this possible?  Would anyone know which menu/submenu/function would need to be excluded to remove the "workflow configuration" html page from this new responsibility.

This is what I currently have :

I want to remove the "workflow configuration" submenu.  I've tried a number of menu exclusions but don't seem to be getting the right one!!  Any help would be much appreciated.