You don't need to do all this, it's what \Q is for!

Perhaps I should have been more explicit...

my $string = 'abcdef';
my $match = '[a-z]';

$string =~ s/\Q$match/NOT REPLACED/;
print "$string\n";
$string =~ s/$match/REPLACED/;
print "$string\n";

__OUTPUT__
abcdef
REPLACEDbcdef
[download]

have a look in ...

perldoc perlre
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