Конвертация matnr в guid

DATA: gv_convert_stock TYPE REF TO /scwm/cl_ui_stock_fields.

IF gv_convert_stock IS INITIAL.
CREATE OBJECT gv_convert_stock.
ENDIF.

CALL METHOD gv_convert_stock->get_matid_by_no
EXPORTING
iv_matnr = p_mat
RECEIVING
ev_matid = ls_aq-matid.