Private Const USERFORM_CLASSNAME = "ThunderDFrame"
Private Const GWL_STYLE = -16
Private Const WS_SYSMENU = &H80000

'// API関数宣言
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" ( _
                                        ByVal lpClassName As String, _
                                        ByVal lpWindowName As String) As Long

Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" ( _
                                        ByVal hwnd As Long, _
                                        ByVal nIndex As Long) As Long

Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
                                        ByVal hwnd As Long, ByVal nIndex As Long, _
                                        ByVal dwNewLong As Long) As Long

Private Declare Function DrawMenuBar Lib "user32" ( _
                                        ByVal hwnd As Long) As Long

'// 以下イベントプロシージャ

Private Sub CommandButton1_Click()
    ' 自フォーム終了
    Unload Me
End Sub

Private Sub U2serForm_Initialize()
    Dim hwnd As Long
    Dim lngRet As Long

    ' ウインドウハンドル取得(Excel2000)
    hwnd = FindWindow(USERFORM_CLASSNAME, Me.Caption)
    ' ウインドウ属性取得
    lngRet = GetWindowLong(hwnd, GWL_STYLE)
    ' ウインドウ属性変更(システムメニュー削除)
    lngRet = SetWindowLong(hwnd, GWL_STYLE, lngRet And Not WS_SYSMENU)

End Sub