I have my products sorted by ascending price (3a) which is fine for most of the products. I have several categories where I'd like to use the PRODUCT SORT ORDER to manually sort these items on the product listing page. I set a SORT ORDER number for all products in a category but they are still using the default sort method.

Is there any way to configure the product listing like this:
USE DEFAULT SORT METHOD WHEN NO SORT ORDER NUMBER IS PRESENT
USE MANUAL SORT METHOD WHEN A SORT ORDER NUMBER IS PRESENT (OVERRIDES DEFAULT)

My deepest appreciation to anyone who can help!!!