Hi,
wa_field_catalog_csv-ref_table = 'ZST_PREISUPLOAD'.
wa_field_catalog_csv-ref_field = 'VKORG'.
APPEND wa_field_catalog_csv TO ta_field_catalog_csv.
CLEAR wa_field_catalog_csv.
wa_field_catalog_csv-ref_table = 'ZST_PREISUPLOAD'.
wa_field_catalog_csv-ref_field = 'MATNR'.
APPEND wa_field_catalog_csv TO ta_field_catalog_csv.
CLEAR wa_field_catalog_csv.
wa_field_catalog_csv-ref_table = 'ZST_PREISUPLOAD'.
wa_field_catalog_csv-ref_field = 'PREIS'.
APPEND wa_field_catalog_csv TO ta_field_catalog_csv.
Try this and check whether it works.
Regards,
K.S.