In the admin, there have been requests to have the custom fields available in the quick entry drop down.
Well, the developer was kind enough to add a really great feature in a recent release.
This is the ability to add any custom database columns some of us might have, to that drop down. Well I just tested and it works fine with the ect custom fields available for your products.
Here are the release notes - https://www.ecommercetemplates.com/support/topic.asp?TOPIC_ID=109004

so for .asp add this to your includes
customquickupdate="pCustom1,pCustom2,pCustom3"

for .php it should be
$customquickupdate="pCustom1,pCustom2,pCustom3";