Solution : https://service.sap.com/sap/support/notes/395311 (SAP Service marketplace login required)
Key words :
fill customer-specific fields, add 'import' parameter i_ci_ekpo, add 'import' parameter i_ci_ekko, additional import parameter, i_ci_ekpo type spec, function module me_create_po_headerpart 2, function module me_create_po_header, function module me_create_po_item, purchase order header, i_ci_ekko typing
Related Notes :
| 445169 | BAPI_PO_GET_DETAIL: Integrated customer enhancements |
| 336589 | BAPI_PO_CREATE: Customer enhancements |