for each workbook in this folder
if workbook.name = "Products D Jan12.xls" then
else
if right(name,2) = 12 then
  open the workbook
hide the row
else
end if
end if
next

Private Sub hideLine25()
    Dim strComputer As String
    Dim objWMIService As Object
    Dim colFiles As Object
    Dim objFile As Object
    Dim wb As Excel.Workbook
    Dim ws As Excel.Worksheet

    Dim strPath As String
    Dim strDrive As String
    Dim strExtension As String
    
    ' drive, path and file extension
    strDrive = "C:"
    strPath = "\Documents and Settings\All Users\Desktop\Products\Jan12\"
    strExtension = "xls"
    
    strComputer = "."
    Set objWMIService = GetObject("winmgmts:" _
                                & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
    Set colFiles = _
    objWMIService.ExecQuery("Select * From CIM_DataFile " & _
              "Where " & _
              "Drive = '" & strDrive & "' " & _
              "And Path = '" & Replace(strPath, "\", "\\") & "' " & _
              "And Extension = '" & strExtension & "'")
              
    For Each objFile In colFiles
        'Debug.Print strDrive & strPath & objFile.Filename & "." & strExtension
        ' check if Crest is in the file name, or it is a temporary excel file
        If (InStr(objFile.Filename, "Crest") = 0) And (InStr(objFile.Filename, "~!") = 0) Then
            Set wb = Application.Workbooks.Open(strDrive & strPath & objFile.Filename & "." & strExtension)
            On Error Resume Next
            ' if our sheet is not found, error message will appear
            ' and we dont want that
            Set ws = wb.Sheets("Historic Sales")
            On Error GoTo 0
            If Err.Number = 0 Then
                ' no error, our sheet was found
                ' then hide it.
                Rows("25:25").Select
                Selection.EntireRow.Hidden = True
                DoEvents
            End If
            Set ws = Nothing
            wb.Save
            wb.Close
            Set wb = Nothing
            DoEvents
        End If
    Next
End Sub