Need advice for notehead replacement

For eartraining and educational purpose I want to create atonal dictations, and I want to replace some notes (notehead) with a “?” or something more graphical, but these replaced’s noteheads must be positioned at the same Y vertical.
Can somebody help me? thanks
best regards

There shouldn’t be any reason why you couldn’t design your own notehead set that includes a question mark notehead. You would need to manually hide the stem using the Hide stem property for the note (which appears only in Engrave mode) but that should be all that’s required. Have you tried it? Let me know where you are running into difficulties.