Hello Doug,
Looking back through previous discussions with you, I see that you are/were using a Mac.
To make macOS launch any given application (such as Hauptwerk) automatically when it boots, you can just launch the application (Hauptwerk), then right-click on its icon in the Mac's Dock at the bottom of the screen, then select the option to launch it automatically at login.
If you then find that Hauptwerk sometimes gets launched before the operating system has finished initialising all of the audio/MIDI devices/drivers, resulting in Hauptwerk displaying a warning as it launches that some audio/MIDI devices appear to be missing, you can then also set the 'Minimum time to wait on start-up' setting on Hauptwerk's 'General settings | General preferences | Advanced ...' screen tab to an appropriate value, to give the operating system more time to finish initialising its audio/MIDI devices/drivers before Hauptwerk queries them.