Just a suggestion - Make a new part, or select an existing part that contains the next rhythm that you want to use. Select from top menu MIDI-> Advanced quantize-> Part to groove .
Select the parts that you want to apply the rhythm to
From MIDI menu select quantize set up. You should see the name of the part used for the groove in the text box in the centre of the panel.
Move the top 3 sliders for position, velocity and length to 100%
Change the max move selector as required and set iterative quantize to 100%
Press apply quantize button.
You may need to remove or add notes before quantizing if your new rhythm has a different quantity of notes. These could be some short notes in roughly the right place. The quantize should change the length/position and velocity of the new notes
Hope this helps