VueScan manual multi frame(crop)

Hey guys,
Just purchased VueScan recently and trying to follow the scanning guide for VueScan + NLP. My problem is that is there a way to manually create a crop?
Looks like VueScan is trying to make everything auto but not letting user to add a manual crop?
Instead of scanning each frame individually, I now got 3 large crop for each film strip. Can I manually make more crops for each individual frame? Thanks.

Does this not help?

Thanks but there is no info about how to manually create a crop (like in Silverfast) :frowning: