POWL architecture in SAP is bit complex, but once you understood the concept how to configure and modify it , it is pretty cool and easy.With the help of this document you would be able to identify the POWL feeder class and other details and control the action for POWL.
1. Login to screen and Rigt click on the POWL query and select technical details.
2. Scroll down the technical details and go to URL start parameter section and get the application id (applid)
3. Now go to the transaction POWL_QUERYR and get query id from the application id . If there are multiple queries check the description and the sequence number. In screen it will appear in the order.Look for query sequence no to get the order of queries
4 Get the Query ID and go to the transaction POWL_QUERY. From this you will ger POWL type ID.
5. Now go to the transaction POWL_TYPE. Here you can see the Feeder class which will supply the details to this POWL. You can copy to Z* and modify for customer specific requirement and modify customization accordingly.
6. To get the actions configured for the POWL and get the field catalog details go to the transaction /SAPSRM/POWL_CUST and give the POWL type id.
to enable or disable actions for the POWL double click on "Actions"
7. To refresh the POWL we modified on the screen do run the report POWL_D01 for the specific user or group of users.
I hope with this you will be able handle POWL requirements in much better way.