So attached is my plugin which adds an "Order No" filter to the batch sales processing screen.
If your filter's stored procedure has the string 'AERP' in the name, it will run a custom version of the candidate population logic, adding the "Order No" filter to the logic. It will also put the Order No into the "Remark" field in the candidate list.
If your filter's stored procedure does not have the string 'AERP' in the name, it will run the standard JIWA logic.
The current use-case for my customer's requirement is the default value for the Order No filter, which is used in a CHARINDEX clause in the stored procedure; this could easily be changed to use a 'LIKE' clause instead.
My stored procedure also returns 'Active' orders and excludes credit notes.
The SQL Script is in the plugin documents. It also includes a test execution of the stored procedure so that you can make sure it's returning useful data before trying to use it in JIWA.
Unlike the manual BO process customisation referenced at the start of this thread, this doesn't need reflection.
I also dabbled with disabling some of the filters, there are some commented-out lines for this in the setup method.