Option Explicit 
 
 '----------------------------------------------------------
 'Must set a reference (Tools | References) to
 'Microsoft Excel 11.0 (or relevent version) Object Library
 '--------------------
 ' Version:
 '  11.0 = 2003
 '  10.0 = 2002 or XP
 '   9.0 = 2000
 '   8.0 = 1997
 '--------------------
 'This will make use of 'Early Binding' and give us access
 'to the Excel Object Model and it's intellisense.
 '----------------------------------------------------------
 
Function IsXLBookOpen(strName As String) As Boolean 
     
     'Function designed to test if a specific Excel
     'workbook is open or not.
     
    Dim i As Long, XLAppFx As Excel.Application, NotOpen As Boolean 
     
     'Find/create an Excel instance
    On Error Resume Next 
    Set XLAppFx = GetObject(, "Excel.Application") 
    If Err.Number = 429 Then 
        NotOpen = True 
        Set XLAppFx = CreateObject("Excel.Application") 
        Err.Clear 
    End If 
     
     'Loop through all open workbooks in such instance
    For i = XLAppFx.Workbooks.Count To 1 Step -1 
        If XLAppFx.Workbooks(i).Name = strName Then Exit For 
    Next i 
     
     'Set all to False
    IsXLBookOpen = False 
     
     'Perform check to see if name was found
    If i <> 0 Then IsXLBookOpen = True 
     
     'Close if was closed
    If NotOpen Then XLAppFx.Quit 
     
     'Release the instance
    Set XLAppFx = Nothing 
     
End Function 
 
Sub TestFunction() 
    MsgBox IsXLBookOpen("Book1.xls") 
End Sub