my $workbook = $format->{class}->new($XLS)
or die "Error opening Excel file: $!";
-my $worksheet = $workbook->add_worksheet(substr($opt{'title'},0,31));
+my $title = $opt{'title'};
+$title =~ s/[\[\]\:\*\?\/\/]//g;
+$title = substr($title, 0, 31);
+my $worksheet = $workbook->add_worksheet($title);
$worksheet->protect();