Option Explicit 
 
Private Declare Function AnimateWindow Lib "USER32" (ByVal hWnd As Long, ByVal _ 
dwTime As Long, ByVal dwFlags As Long) As Boolean 
 
Private Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal _ 
lpClassName As String, ByVal lpWindowName As String) As Long 
 
Const AW_CENTER = &H10 'Collapse inward
Const AW_HIDE = &H10000 'Hide
 
Private Sub Workbook_BeforeClose(Cancel As Boolean) 
    Dim lngFrmWindow As Long 
     'Retrieve a handle to Excel
     'XLAMIN is the Class name for Excel 2000/2002
     'Application.Name & " - " & ActiveWorkbook.Name
     'retrieves Excel's window title text, this is what we need
    lngFrmWindow = FindWindow("XLMAIN", Application.Name & " - " & ActiveWorkbook.Name) 
     
    If lngFrmWindow <> 0 Then 'lngFrmWindow returns a zero if there's an error
         'Make Excel Collapse inwards and exit
         '750 is in milliseconds the time length of the animation
        AnimateWindow lngFrmWindow, 750, AW_CENTER Or AW_HIDE 
    Else 'An error has occured with the AnimateWindow function
        Call MsgBox("There was an error when trying to animate the Excel window." _ 
        & vbCrLf & "" _ 
        , vbCritical, Application.Name) 
         
    End If 
     'Quit Excel
    Application.Quit 
End Sub