is there a way to notate a roll in a percussion part?
The usual way is to put the repeated notes on a hidden, playing staff and use glyphs from Boxmarks2, Bach or one of Lawie's fonts to decorate the stem(s) of muted notes on a visible staff. If you are still unsure, attaching a small image of what need will probably get you a more specific response
To expand on Rick's response, you would use
o for a roll in -Dings and Boxmarks.
If User1 is -Dings, this is what I'd use-just copy, paste, and Ctrl-Shift-↕ to move it:
!NoteWorthyComposerClip(2.0,Single)
|Text|Text:"o"|Font:User2|Pos:-3|Justify:Right|Placement:AtNextNote
|Note|Dur:4th|Pos:4
|Text|Text:"o"|Font:User2|Pos:-3|Placement:AtNextNote
|Note|Dur:4th|Pos:-4
!NoteWorthyComposerClip-End
thanks kahman. thats exactly what i needed. thanks to you too rick.