Text above a vertically shifted MultiMeasureRest

[Paolo Prete]

Hello,

How can I put a text above a MultiMeasureRest, and not above the staff?
This would be useful for cross-staff MultiMeasureRests; for them I normally
use the Y-offset property in order to shift them down, as shown in the
below code:

{ \override MultiMeasureRest.Y-offset = #-5 \time 2/4 R2^\markup { \italic
"ad lib." } }

Thanks!