I need a BAPI or function that can create a PO without the purchase req.

I need a BAPI or function that can create a PO without the reference to a purchase requisition. We are creating "direct POs" (with no reference to PR) manually. And we have a large amount of documents to create. I can't figure out if BAPI_PO_CREATE and BAPI_PO_CREATE1 can help us by doing this, because I've understood this BAPIs creates POs only with the reference to a purchase requisition.

Thanks in advance!!

Sebastian