Thank you for the comments and help which stopped m looking in crypts that would have nothing in them!
I have done more work and to help I used the sub below.
I believe that I have found that the problem was caused by having a directory
that contained ‘[]’ characters since when I removed these all was well.
It would interesting to know if these characters are not ‘preferred’ in some sense.
To confuse matters, I have a suspicion that this will not be found on all PCs under windows but I cannot be sure

sub copy_edit_savesp_test($$$) {

my ($file_name, $dir_in, $dir_out) = @_;

my ($file_name_in_full, $file_name_out_full, $excel, $excel_res, $work
+book, $copy_res);
my ($add_data_sp, $row, $workbook_res, $ew_message, $wksht, $wksht_str
+, $worksheet);

$file_name_in_full = $dir_in . '\\' . $file_name;
$file_name_out_full = $dir_out . '\\' . $file_name;

$copy_res = copy($file_name_in_full, $file_name_out_full);

print "\ndir file <$file_name>\nin <$dir_in>\n$dir_out\n";


print "\n[copy_edit_savesp_test] copy res <$copy_res> for <$file_name_
+out_full>\n";


$excel_res = 1;

$excel = Win32::OLE->new('Excel.Application', 'Quit') or ($excel_res =
+ 0, $ew_message = "Could not create excel object");

print "[copy_edit_savesp_test] open res <$excel_res> excel <$excel> wo
+rkbook <$workbook>\n";

if($excel_res == 1) {

    $workbook_res = 1;
    $ew_message = "work book ok";

    $workbook = $excel->Workbooks->Open($file_name_out_full)  or ($wor
+kbook_res = 0, $ew_message = "Could not open excel workbook");

    print "[copy_edit_savesp_test] after workbook result <$workbook_re
+s> message <$ew_message>\n";

    $add_data_sp = 'yes';

    if($add_data_sp eq 'yes') {

        $wksht +=1;
        $wksht_str = "sheet" . $wksht;

        $worksheet = $excel->ActiveWorkbook->Worksheets($wksht_str);

        $row = 2;
        $worksheet->Cells($row,9)->{Value} = "row $row 9";

        $row = 3;
        $worksheet->Cells($row,6)->{Value} = "row $row 6";

        $worksheet->Cells($row,8)->{Value} = "row $row 8";

    } else {

        print "\n[copy_edit_savesp_test]no data added to spredsheet\n"
+;
    }
}


$excel->{DisplayAlerts}=0;   

$ew_message = "just before saving spreadsheet";
print "before message <$ew_message>\n";

$excel_res = 1;
$excel->Workbooks(1)->SaveAs($file_name_out_full)  or ($excel_res = 0,
+ $ew_message = "Could not save spreadsheet>");

print "[copy_edit_savesp_test] after saving spredsheet result <$excel_
+res> message <$ew_message>\n\n";

$excel->{DisplayAlerts}=1;   



}
[download]