Win8 Strawberry 5.8.9.5 (32)  Fri 08/19/2022 19:42:14
C:\@Work\Perl\monks
>perl
use strict;
use warnings;

my $txt = "C:\\Book\\C0001-Chapter-001.mp3";
my $new = "C:\\Book\\NEW-C0001-Chapter-001.mp3";

print "\n";
print "Before: '$txt' \n";

# Workaround -- use \Q \E -- see quotemeta.
$txt =~ s/\Q$txt\E/$new/;

print "After:  '$txt' \n";
print "\n";
^Z

Before: 'C:\Book\C0001-Chapter-001.mp3'
After:  'C:\Book\NEW-C0001-Chapter-001.mp3'