Hello Marcelo11756,
You mentioned that you want the report with Completed Workorder in the specified daterange. In that case you dont have to add any button you can produce that report based on the stock screen.
Firstly, select the date range(From Date and To Date) on the Existing Workorder Screen, then on the Status filter type "Completed". It will filter all the workorder based on Completed status.
Select the Workorders, then Click on the third tab Print/Email, then click on Selected only and then click on Job Cost Profitability by Customer button. This will generate the desired report.
I hopr this helps!
-INder