open my $csv_fh, '<', 'input.csv';
    open my $tff_fh, '>', 'output.tff';

    my $field = qr{ " (?<field> [^"]* ) " | (?<field> [^,"]* ) }x;

    while (my $line = <$csv_fh>) {
        $line =~ s{   $field     (?<comma> ,?)        }
                  { $+{field} . ($+{comma} && chr 31) }gxe;

        $line =~ s{\n}{chr 30}xe;

        print {$tff_fh} $line;
    }