Hi,
If you like trigger the ENTER KEY programatically you can achieve it by using the below code
CALL METHOD cl_gui_cfw=>set_new_ok_code
EXPORTING
new_code = 'OK'.
Assign the Function Code 'OK' in the GUI STATUS for Tick Icon in the Standard toolbar.
We used this when dealing with Events in ALV and it triggered the PAI for somewhat similar requirement as above.
Regards,
Vasanth