unless (defined $excel)
	{
		eval 
		{
			$excel = Win32::OLE->GetActiveObject('Excel.Application')
		};
		die "Excel not installed" if $@;
	}
	
	unless (defined $excel) 
	{
	    $excel = Win32::OLE->new('Excel.Application', 'Quit')
			    or die "Oops, cannot start Excel";
	}
	#to avoid excessive dialogs when saving in non-Excel format
	$excel->{DisplayAlerts} = 0;

    	#$excel->Workbooks->Open({ FileName => $fullname_input_file })
	#|| print STDERR "didnt open the file $!\n";

	# get a new workbook
	my $wbook; 	
	if($wbook = Win32::OLE->GetObject($fullname_input_file)){;}
	else 
	{
		$wbook = $excel->{Workbooks}->{"$fullname_input_file"};
		if($wbook->Activate()){;}
		else
		{
			print STDERR "Could not open the file $fullname_input_file: $!\n";
			exit;
		}
	}