If I understand you correctly, what you are proposing may be unnecessarily complicated. Just make a format column the way chaley suggested. To view one format only, open the Tag browser (the button with the little luggage tag on it), click on the Format bitton, then click on the one you want to display. That will display only the books with that format.
Of course, I may have totally misunderstood you.
I hope your little girl is feeling better.