function DlgFunc(hw: hWnd; uMsg: DWORD; wParam: wParam; lParam: lParam): bool; stdcall;
var
  hMenue: HMENU;
  p: TPoint;
begin
  Result := True;
  case uMsg of
    WM_INITDIALOG:
      begin
        hMenue := CreatePopUpMenu;
  
        // Menüs mit Einträgen füllen
        AppendMenu(hMenue, MF_STRING, IDM_ITEM1, '1');
        AppendMenu(hMenue, MF_STRING, IDM_ITEM2, '2');

        // SetMenu(hW, hMenue);
      end;

    WM_CONTEXTMENU:
    begin
        GetCursorPos(p);
        TrackPopupMenu(hMenue, TPM_RIGHTALIGN or TPM_RIGHTBUTTON, p.x, p.y, 0, hW, nil);

        {$IFDEF DEBUG} showmessage(format('%d, %d ', [p.x,p.y])); {$ENDIF}
    end;

    //...

    WM_DESTROY:
      begin
        DestroyMenu(hMenue);
        PostQuitMessage(0);
      end;
  else
    result := false;
  end;
end;

BEGIN
  InitCommonControls;
  hdlg := DialogBoxParam(HInstance, MAKEINTRESOURCE(100), 0, @DlgFunc, 0);
END.

var
  hMenue: HMENU; // <---<<

function DlgFunc(hw: hWnd; uMsg: DWORD; wParam: wParam; lParam: lParam): bool; stdcall;
  p: TPoint;
begin
  //...