#!/usr/bin/perl

use strict;
use warnings;

use File::Basename;
use File::Find::Rule;

my @files = File::Find::Rule->file()
    ->in( 'c:/test/');

foreach my $file ( @files ) {

    my ( $old_name, $path ) =
        File::Basename::fileparse( $file );
    
    my $new_name = $old_name;

    $new_name =~ s/^ABC/ABCD/;
    $new_name =~ s/^XYZ/XYZD/;

    next if $new_name eq $old_name;

    rename( $path . $old_name, $path . $new_name ) 
        or die "Renaming $old_name to $new_name: $!";

    # or copy, as per your update
    # require File::Copy;
    # File::Copy::copy( $path . $old_name, $path . $new_name )        
    #    or die "Renaming $old_name to $new_name: $!";
}
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