try this new code, that would rename your file, You need to check the contents of g4 as we are using that to replace the month_year part of your file.


Sub macro_1()
Dim fl_name As String
Dim target_str As String
  
  Dim wb1, wb2, month_name, fs, fol, fil
  Set wb1 = ActiveWorkbook
  Set fs = CreateObject("Scripting.filesystemobject")
  Set fol = fs.getfolder("U:\Outlooksoft\Europe\2013\Financial Reporting\ACTUAL Monthly results\12_Dec_13\Manager Expense Reports\Corp") ' change path as appropriate

  For Each fil In fol.Files
      Set wb2 = Workbooks.Open(fil)
     wb2.Sheets("PERIODIC").Range("B63") = wb1.Sheets("Sheet1").Range("G4")
     Application.Run ("mnu_etools_refresh")
      Application.DisplayAlerts = False
    'new code added
    fl_name = wb2.Name
    If InStr(1, fl_name, "_") > 0 Then
    target_str = Mid(fl_name, InStr(1, fl_name, "_") - 3, 6)
    'MsgBox wb1.Sheets("Sheet1").Range("G4")
    fl_name = Replace(fl_name, target_str, wb1.Sheets("Sheet1").Range("G4").Text)
    End If
    fl_name = ActiveWorkbook.Path & "\" & fl_name
    'new code ends
     wb2.Close True
     fs.movefile fil, fl_name
    Application.DisplayAlerts = True
 Next

End Sub