Hide and replace a note with text

[Rajesh Baskar]

Hi,

Can you hide and replace a note with a question mark? I kind of achieved 
this with the below example. But the question mark is not in place of 
the note, it appears below the staff. I can use \override 
TextScript.extra-offset = #'(0 . 4.275) to achieve this but I don't want 
to hard code the offset as the note to hide can appear anywhere on the 
staff.

     \version "2.22.0" \include "english.ly"
     \header { tagline = "" }
     \score {\new Staff \with {\remove "Time_signature_engraver" }
             {\set Staff.midiInstrument = #"Acoustic Grand Piano"
              \key c \major \time 5/1 \clef bass f1 g
        \hideNotes a-\markup {\fontsize #7 \with-color "#6A00F4" "?" }
        \unHideNotes
        bf c' \bar "||"}  \layout { }
            \midi { \tempo 4 = 168}}


Thanks for the help.

Dav