Option Explicit

Private Const mcClassnameMSExcel = "XLMAIN"
Private m_strText As String

Private Declare Function KillTimer Lib "user32.dll" (ByVal hwnd _
      As Long, ByVal nIDEvent As Long) As Long

Private Declare Function SetTimer Lib "user32.dll" (ByVal hwnd _
      As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, _
      ByVal lpTimerFunc As Long) As Long

Private Declare Function FindWindow Lib "user32.dll" Alias _
      "FindWindowA" (ByVal lpClassName As String, _
      ByVal lpWindowName As String) As Long

Public Sub ShowDialogAPITimer()
  Load frmAPITimerCaption
  m_strText = frmAPITimerCaption.Caption
  frmAPITimerCaption.Show
End Sub

Public Sub prcSetTimer()
  SetTimer FindWindow(mcClassnameMSExcel, Application.Caption), _
        0&, 100&, AddressOf prcTimer
End Sub

Private Sub prcTimer(ByVal hwnd As Long, ByVal nIDEvent As Long, _
      ByVal uElapse As Long, ByVal lpTimerFunc As Long)

  m_strText = Right$(m_strText, Len(m_strText) - 1) & _
        Left$(m_strText, 1)
  frmAPITimerCaption.Caption = m_strText
End Sub

Public Sub prcKillTimer()
  KillTimer FindWindow(mcClassnameMSExcel, Application.Caption), 0&
End Sub

Option Explicit

Private Sub UserForm_Activate()
  Call prcSetTimer
End Sub

Private Sub UserForm_Terminate()
  Call prcKillTimer
End Sub