[Creat0R]

Можно по PID:

Код:

#NoTrayIcon
#include <SysTray_UDF.au3>
;

$Pid = ProcessExists("Opera.exe")

If Not $Pid Then
    MsgBox(16, "Error", "This process not exists")
    Exit
EndIf

$Index = _SysTrayIconIndex($Pid)

If @error Then
    MsgBox(16, "Error", "This process not have tray icon")
    Exit
EndIf

_SysTrayIconClick($Index, "Right")

If @error Then
    MsgBox(16, "Error", "There was an error to click on the icon")
    Exit
EndIf

Func _SysTrayIconClick($iIndex, $sButton="Main")
    Local $TrayIcon_Pos = _SysTrayIconPos($iIndex)
    If Not IsArray($TrayIcon_Pos) Then Return SetError(1, 0, 0)

    Local $Old_Mouse_Pos = MouseGetPos()
    MouseClick($sButton, $TrayIcon_Pos[0], $TrayIcon_Pos[1], 1, 0)
    MouseMove($Old_Mouse_Pos[0], $Old_Mouse_Pos[1], 0)
EndFunc

Рабочий SysTray_UDF.au3 (для последней версиии аутоита) прикрепил к сообщению.