>>Is there an event/method to call or a property to set in order to programmatically open a combobox? I can't seem to find one. I would think calling the click() or downclick() method would work, but nothing happens.
>use keyboard '{x41A0}' in the gotfocus event. Combo will open on entry and close on exit.
>HTH

Also, you could use
mouse click at this.top+25,this.left+this.width-5 pixels
in Combo.Gotfocus event