How to exclude on hand quantities found in specific bins, listed in a custom record in itemlocations script suitescript 2.0

Please if anyone can suggest how to do it properly. I have created a new search in the script found the fields for locations and bins and tried to do it with  new search created and with if else statement but does not work. I know it is a long shot for explanation, but if someone done something similiar and is able to help I would much appreciate it. The idea is there are times when we have parts that have been found with bad
quality, so we’ll pull them from the main location, & move them to “X” or “Y” locations while
we wait to figure out how to handle the bad parts. Currently, those bad parts are still lumped together
with all of the other good parts & the on-hand number may not be entirely correct. I need the following logic in the itemlocations script
Total the On Hand quantity, of an item, by “Location” and “Bin”, from the inventory detail record.
In this process test to see if “Location” and “Bin” are found in the custom record, and if found exclude the on-hand quantity of this location and bin from the total on-hand
quantity for the item.

Thank you in advance!