How to update RCV_SHIPMENT_HEADERS(descriptive flex field) from front end (Where we enter)

 We are facing an issue on continuous basis that when we make receipt Purchasing >>> receipt>>>RCV_SHIPMENT_HEADERS(DFF).WE fill this DFF but some how we have to change the values against this DFFHow it is possible that we can update this DFF from the front end window .Now we are updating from the sql.

Thanks