Here's my stab at it. If it's not what you need, please let me know.

#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper::Concise;

my @row = q(aa, bb, \\c\c\, d\d);
foreach (@row) {
  s/(\\+)/$1$1/;
}
print Dumper(join(',', @row));
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