Option Explicit
Private Declare Function ClientToScreen Lib "user32" (ByVal hWnd As Long, _
  lpPoint As POINTAPI) As Long
 
Private Type POINTAPI
  X As Long
  Y As Long
End Type
 
Dim MnuPopup As MenuItem
 
Private Sub Command1_Click()
  Dim P As POINTAPI
 
  P.X = 0
  P.Y = Command1.Height / Screen.TwipsPerPixelY
  ClientToScreen Command1.hWnd, P
 
  MenuBar1.Popup MnuPopup, P.X, P.Y, TPM_LEFTALIGN Or TPM_TOPALIGN
End Sub
 
Private Sub Form_Load()
 
  With MenuBar1.MenuItems
    ' Hier kommt es bei mir zum Laufzeitfehler 13!?
    Set MnuPopup = .AddPopup("MenuPopup")
 
    .
    .
    .
  End With
End Sub