PFCSIG Opening DDDW using key controls

[O.S.Thanikachalam]

Dear all,   I am in need of triggering the  mouse clicked event (without using the mouse) of the DDDW down arrow button (opening the list box) by using a trigger event (Control + enter combination) when the focus is at that DDDW. I think, it can be triggered by calling the 'other' event.   If it is possible what are values for the wparam and lparam. Please also let me know where I can find the documentation for the other event.   Regards,   Thani