markup position

[LEGRAND Jean-Marc]

Hi again !
I'd like to put a markup dot like this :

s4_\markup {\raise #20.0 \musicglyph #"dots-dot"}

so that it appears on the same line as an a2 just before. But the dot appears 
below the staff, even
after my \raise #20.0.

Does anyone know a trick to raise a markup wherever within the staff ?

Thanks to all for this mailing list !