Besides the obvious that others already correctly posted, please have Text::CSV do the line-endings, not perl:

my $parser = Text::CSV->new ({
    auto_diag           => 1,
    quote_char          => "'",
    allow_loose_quotes  => 1,
    allow_loose_escapes => 1,
    allow_whitespace    => 1,
    });

open my $fo, ">", $outfile or die "$outfile: $!\n";
open my $fh, "<", $file    or die "$file: $!\n";
while (my $row = $csv->getline ($fh)) {
    print $fo (join "@" =>
        $row->[0],
        $row->[1] . $row->[2],
        $row->[3],
        $row->[17],
        $row->[18],
        ), "\n";
    }
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