Динамическое изменение наименования Select-Options и Заголовка блока

SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME TITLE b1_ttl.
    SELECT-OPTIONS: so_equnr FOR mara-equnr.
SELECTION-SCREEN END OF BLOCK b1.

AT SELECTION-SCREEN OUTPUT. 
    %_SO_EQUNR_%_APP_%-TEXT = 'Ед. оборудов.'.
    b1_ttl = 'Доп. поля'.

SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME TITLE b1_ttl.

SELECT-OPTIONS: so_equnr FOR mara-equnr.

SELECTION-SCREEN END OF BLOCK b1.

AT SELECTION-SCREEN OUTPUT.

%_SO_EQUNR_%_APP_%-TEXT = 'Ед. оборудов.'.

b1_ttl = 'Доп. поля'.