Updating New QTY at saving of PR in ME51n and saving PO in ME21n

Hello,

     I have a requirement where a PR for Service is created in ME51n.

The User enters a single line in line item as service. In line item details a tab with services table is maintained (ESLH, ESLL).

But in the line item the qty is set to 1 instead of total qty of that services inside that line item.

I checked with ME_PROCESS_REQ but I can't get the services there or the packno through which I can get the services of that line item and update the qty therein.

Any other BADI, USEREXIT or enahancement that woud allow me to do so.

And I need similar check when creating PO against this service PR.