User Exit to add user-defined selection critieria onto VL10G

Does anyone know how to add user-defined selection criteria onto <b>VL10G</b> - Sales and purchase order display screen? OSS note <b>524424</b> states the userexit to transfer user-defined selection criteria from the selection screen to the report but no information on how to add the selection criteria on the screen. Is that something can be done through configuration or user-exit?

Any advice or sample is greatly appreciated.