Run-tine error '49':
Bad DLL Calling convention

Option Explicit

Private Sub Form_Initialize()
    ' Запускаем субкласс
    wlOldProc = SetWindowLong(hWnd, GWL_WNDPROC, AddressOf wlNewProc)
End Sub

Option Explicit

Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long

Public Declare Function GetMenu Lib "user32" (ByVal hWnd As Long) As Long
Public Declare Function MenuItemFromPoint Lib "user32" (ByVal hWnd As Long, ByVal hMenu As Long, ptScreen As POINTAPI) As Long

Public Const GWL_WNDPROC As Long = - 4 
Public wlOldProc As Long

Public Const WM_NCMOUSEMOVE = &HA0
Public Const HTMENU =  5 

Public Type POINTAPI
        x As Long
        y As Long
End Type


'/*
' Новая оконная процедура
Public Function wlNewProc(ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Dim PAPI As POINTAPI, i As Long
    Select Case wMsg
        Case WM_NCMOUSEMOVE
            If wParam = HTMENU Then 'hit-test value
                PAPI = MakePoints(ByVal lParam)
                'Debug.Print "X="; PAPI.x; "Y="; PAPI.y
                Debug.Print "Menu position:"; MenuItemFromPoint(ByVal hWnd&, ByVal GetMenu(ByVal hWnd), PAPI)
            End If
    End Select
    wlNewProc = CallWindowProc(wlOldProc, hWnd, wMsg, wParam, lParam)
End Function
'/*
Public Function LoWord(LongIn As Long) As Integer
     If (LongIn And &HFFFF&) > &H7FFF Then
          LoWord = (LongIn And &HFFFF&) - &H10000
     Else
          LoWord = LongIn And &HFFFF&
     End If
End Function

'/*
Public Function HiWord(LongIn As Long) As Integer
     HiWord = (LongIn And &HFFFF0000) \ &H10000
End Function

'/*
Public Function MakePoints(ByVal lParam As Long) As POINTAPI
    MakePoints.x = LoWord(lParam)
    MakePoints.y = HiWord(lParam)
End Function

Public Declare Function MenuItemFromPoint Lib "user32.dll" (ByVal hWnd As Long, ByVal hMenu As Long, ByVal X As Long, ByVal Y As Long) As Long

Debug.Print "Menu Item position:"; MenuItemFromPoint(ByVal hWnd&, GetMenu(ByVal hWnd&), ByVal PAPI.X, ByVal PAPI.Y)