How do I copy particular extension files recursively and store it in same folder structure?

Code:
 
    use strict;
    use warnings;

    my $pwd         = "/home/ra/DEMO";
    my $destination = "/home/ra/output";

    opendir(DIR, "$pwd") or die "Error";
    my @files = readdir(DIR);
    closedir(DIR);

    foreach my $file ( @files
...