prueba asi y debe llamar al codigo q le das click
FORM USER_COMMAND USING P_UCOMM LIKE SY-UCOMM
P_SELFIELD TYPE SLIS_SELFIELD.
CASE P_UCOMM.
WHEN '&IC1'. " SAP standard code for double-clicking
CHECK NOT P_SELFIELD-value IS INITIAL.
*identifica el registro q has dado click
READ TABLE IT_OUT INDEX P_SELFIELD-tabindex.
*capturado el registro pasa como parametro a la Tx.
SET PARAMETER ID 'EBELN' FIELD P_SELFIELD-VALUE.
CALL TRANSACTION 'ME23N'.
ENDCASE.
ENDFORM