Hello Lawrence,
Hauptwerk's 'master scoped combinations' are there for that purpose -- you can programme their 'scopes' to make them divisionals (or to affect any other subsets of the stops that you like). The 'Registration menu: master scoped combinations' section in the user guide covers them (pages 101-105 in the current v4.2.1 version).
As with the master generals, there are mini control panels for them, and you can assign them to piston toolbar buttons.