Is there a way to only copy the active notes of a shortened pattern?

If I record a 32 step pattern and than shorten it to 16 beats. And copy the 16 beats to a new pattern. If I then change the length to 32 is there a way to just duplicate the first 16 notes as it would do with an empty pattern? Currently the hidden (17-32) notes remain in the pattern if copied. I want to only copy a section of the pattern (the active steps).