marimba left and right hand notations for different note types

Mornin'

I'm putting in some UIL marimba parts for my son to practice. Throughout the notation, it has 8th notes with one hand and quarter notes with the other--doesn't matter which for this discussion.

Musecore wants to just show the quarters as a part of the 8ths--using the same stem and rail.

However, on the printed music the quarters and respective 8ths are stemming in different directions to make them easier to see.

I can drag the rails up or down, but i cannnot make quarter notes on (say) 1 and 3 look like that (with quarter rests) while the other hand plays straight 8ths to the bar.

I forgot to add that these are also in the same clef.

I will be looking through the archives to see if there is mention of this already.

thanks