Hiding empty bars

Hi guys!
In my 32-bar score, there is a solo instrument that is silent for 28 bars. The solo only starts at bar 29. Tell me Please how can I hide these 28 bars?
Or another option, how can I add an extra staff, but only from bars 29 to 32?
For example, above the staff of the first violins, I need to add an additional staff for the solo violin, but only from 29 to 32 measures.