use Win32::OLE;

      my $xlApp = Win32::OLE->new('Excel.Application');

      $xlApp->{Visible} = 0;

      $xlApp->{DisplayAlerts} = 0;

      # Open excel file.
      my $xlBook = $xlApp->Workbooks->Open("C:\\Documents and Settings\\username\\Desktop\\testfile.xls");
      my $Sheet1 = $xlBook->Worksheets(1);

        my $row = 1;
        my $col = 1;

       $Sheet1->Cells($row,$col)->{'Value'} = 5;

        if (Win32::OLE->LastError) 
        {
                print "File protected";
        }

      $xlBook ->Close();

  undef $xlBook;