求高手来帮我改一改

文件夹里有多个excel表格，批处理，得到每个表格的行数，没有加密的表格文件可以一直运行，如何修改遇到加密的表格文件继续运行？
Set fs = CreateObject("scripting.FileSystemObject")
Set excel = CreateObject("excel.application")
Set resultBookSheet = excel.Workbooks.Add().Sheets(1)
excel.visible = true
resultBookSheet.Visible = True
resultBookSheet.activate
i = 1
For Each fileName In fs.GetFolder(CreateObject("WScript.Shell").CurrentDirectory).Files

If Right(fileName, 4) = ".xls" Then

Set book = excel.Workbooks.Open(fileName)

resultBookSheet.Cells(i, 1) = fs.getfileName(fileName)

For Each sheet In book.Sheets
resultBookSheet.Cells(i, 2) = sheet.Name

resultBookSheet.Cells(i, 3) = sheet.UsedRange.Rows.Count + sheet.UsedRange.Row - 1

i = i + 1
Next

book.Close False

Set book = Nothing
End If
Next