Displays a shortcut menu at the specified location
#include <GuiMenu.au3>
_GUICtrlMenu_TrackPopupMenu ( $hMenu, $hWnd [, $iX = -1 [, $iY = -1 [, $iAlignX = 1 [, $iAlignY = 1 [, $iNotify = 0 [, $iButtons = 0]]]]]] )
| $hMenu | Handle to the shortcut menu to be displayed | 
| $hWnd | Handle to the window that owns the shortcut menu | 
| $iX | [optional] Specifies the horizontal location of the shortcut menu, in screen coordinates. If this is -1, the current mouse position is used.  | 
| $iY | [optional] Specifies the vertical location of the shortcut menu, in screen coordinates. If this is -1, the current mouse position is used.  | 
| $iAlignX | [optional] Specifies how to position the menu horizontally: 0 - Center the menu horizontally relative to $iX 1 - Position the menu so that its left side is aligned with $iX 2 - Position the menu so that its right side is aligned with $iX  | 
| $iAlignY | [optional] Specifies how to position the menu vertically: 0 - Position the menu so that its bottom side is aligned with $iY 1 - Position the menu so that its top side is aligned with $iY 2 - Center the menu vertically relative to $iY  | 
| $iNotify | [optional] Use to determine the selection withouta parent window: 1 - Do not send notification messages 2 - Return the menu item identifier of the user's selection  | 
| $iButtons | [optional] Mouse button the shortcut menu tracks: 0 - The user can select items with only the left mouse button 1 - The user can select items with both left and right buttons  | 
| Success: | If $iNotify is set to 2, the return value is the menu item identifier of the item that the user selected. If the user cancels the menu without making a selection or if an error occurs, then the return value is zero. If $iNotify is not set to 2, the return value is 1. | 
| Failure: | 0. | 
Search TrackPopupMenu in MSDN Library.
#include <GUIConstantsEx.au3>
#include <GuiMenu.au3>
#include <WinAPIError.au3>
#include <WindowsNotifsConstants.au3>
Global Enum $e_idOpen = 1000, $e_idSave, $e_idInfo
Example()
Func Example()
    ; Create GUI
    GUICreate("Menu", 400, 300)
    GUISetState(@SW_SHOW)
    ; Register message handlers
    GUIRegisterMsg($WM_COMMAND, "WM_COMMAND")
    GUIRegisterMsg($WM_CONTEXTMENU, "WM_CONTEXTMENU")
    ; Loop until the user exits.
    Do
    Until GUIGetMsg() = $GUI_EVENT_CLOSE
EndFunc   ;==>Example
; Handle WM_COMMAND messages
Func WM_COMMAND($hWnd, $iMsg, $wParam, $lParam)
    #forceref $hWnd, $iMsg, $lParam
    Switch $wParam
        Case $e_idOpen
            _WinAPI_ShowMsg("Open")
        Case $e_idSave
            _WinAPI_ShowMsg("Save")
        Case $e_idInfo
            _WinAPI_ShowMsg("Info")
    EndSwitch
EndFunc   ;==>WM_COMMAND
; Handle WM_CONTEXTMENU messages
Func WM_CONTEXTMENU($hWnd, $iMsg, $wParam, $lParam)
    #forceref $hWnd, $iMsg, $lParam
    Local $hMenu
    $hMenu = _GUICtrlMenu_CreatePopup()
    _GUICtrlMenu_InsertMenuItem($hMenu, 0, "Open", $e_idOpen)
    _GUICtrlMenu_InsertMenuItem($hMenu, 1, "Save", $e_idSave)
    _GUICtrlMenu_InsertMenuItem($hMenu, 3, "", 0)
    _GUICtrlMenu_InsertMenuItem($hMenu, 3, "Info", $e_idInfo)
    _GUICtrlMenu_TrackPopupMenu($hMenu, $wParam)
    _GUICtrlMenu_DestroyMenu($hMenu)
    Return True
EndFunc   ;==>WM_CONTEXTMENU