Hi Sid!
I doubt you can change the status with a BAPI - the fields can't be changed in a transaction, so they won't be changeable in a BAPI.
You might use direct database updates - but you might run into consistency problems with this: there might be follow on documents, where archiving still isn't deleting them.
Have a look, if some 'delivery complete' (in the purchase order field ELIKZ) can be set or if some dummy goods receipts will change the status of the documents to be archiveable. This will be a much better solution.
At least check all tables of the corresponding archiving object - you might need to adjust much more than just inbound deliveries to get a successful archiving.
Regards,
Christian
