This should do what you asked for.
1. Create a NoteOn/NoteOff button and set its note value to zero.
2. Create a note transpose slider and press no to the dialog that offers to set the preferred default values so that your slider has values from 0 to 127 and make sure it has that many ticks.
3. Create the momentary button that you will press for sort or long durations and make sure it's Max value is the amount you want velocity to be.
Make 3 a super control for 2 and 1 and make 2 a super control for 1. Now every time you press 3, button 1 will increment by one note and with the duration you keep 3 pressed.
You can adjust 2 (the slider) to set the starting position of your NoteOn button (1)