Getting The Window Handle Of All The Open Workbooks

I am trying to get the caption that is displayed on each window of all the open workbooks. I am using the code below to loop through all the workbook windows, get their handles and finally display their respective captions on a Msgbox.

I am having 2 problems:

1- The code loops only once instead of once for each open workbook !
2- The Msgbox displays an empty string instead of the workbook caption !

If I am not mistaken, problem 2 is due to the fact that the Class name"EXCEL7" used in the code refers to a worksheet and not to a workbook. The trouble is I can't figure out what a Workbook Class name is so that I can use it in the FindWindowEx Function



Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" _
(ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long

Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" _
(ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long

Private Sub CommandButton1_Click()
**Dim BookNameLenghth As Long
**Dim strBuffer As String
**Dim bBufferSize As Long
**Dim lParent As Long
**Dim lChild As Long