#include <Sendmessage.au3>
$hForm = GUICreate("Gui")
$Button = GUICtrlCreateButton("Button", 100, 100, 100, 100)
GUISetState(@SW_HIDE, $hForm)
_SendMessage($hForm, 0x0111, $Button, GUICtrlGetHandle($Button)) ; $WM_COMMAND = 0x0111
Do
Switch GUIGetMsg()
Case $Button
ConsoleWrite("Click")
Case -3
Exit
EndSwitch
Until 0