Hi Praveen,I am able to find the solution, by passing the External number to BAPI_SALESORDER_CREATEFROMDAT2.You have to pass external sales order number in the field - salesdocumentincall function 'BAPI_SALESORDER_CREATEFROMDAT2'exportingsalesdocumen...

Thanks .  Thanks for sharing such a Valuable information on BTP. Love to here more on BTP basics from your side as I am novice on this topic.

Thanks