$ perl -E '
> @row = (
>    q{aa},
>    q{bb},
>    qq{\x5c\x5cc\x5cc\x5c},
>    qq{d\x5cd},
>    );
> say qq{@row};
> s{\x5c}{\x5c\x5c}g for @row;
> say qq{@row};'
aa bb \\c\c\ d\d
aa bb \\\\c\\c\\ d\\d
$