[Topic moved here.]
Only the Swell division is under expression on the St. Anne's organ (real, and also virtual); there's no simple way to alter the sample set to put the other divisions under expression, I'm afraid. (You could potentially instead use the Custom Organ Design Module's -- CODM's -- example organ definition file version of the organ, and modify a copy of that to change its ranks to be enclosed. That involves a bit of XML/SQL editing/programming, and so is a bit more fiddly. See the CODM user guide on the Help menu if you want to go down that route.)
With the standard St. Anne's organ, you could potentially instead auto-detect your MIDI expression pedal to the master volume slider on the 'Audio, MIDI and performance' large control panel (which can be opened via the View menu in Hauptwerk). If you do that, then also right-click on the virtual Swell pedal and clear the MIDI settings for it, so that your MIDI pedal isn't controlling both simultaneously. However, note that the master volume slider simply controls the overall output amplitude of everything simultaneously (even the blower), whereas the virtual Swell pedal models the frequency/phase response of the Swell box, as well as affecting the wind model slightly. Hence the Swell pedal is likely to be noticeably more realistic.
rainyglade wrote: My Great keyboard in Hauptwerk is very soft, almost inaudible.
... but is there a way to make my Great keyboard louder? I can barely hear it.
It's possible to adjust the amplitudes of ranks via the Voicing screen (Advanced Edition) on the 'Organ settings' menu, but with default settings (voicing and rank routing), the St. Anne's Great division is at least as loud as the Swell division.
Are you perhaps routing the Great's ranks to different audio outputs/amplifiers? (With default settings all ranks play through just a single stereo pair.)