#!/usr/bin/perl -w
use strict;

my $tokens = "32,15,4,72,13,28,14";
my @tokens = split (/,/, $tokens);

my $list = "4,13,15";
my @list = split (/,/,$list);
my %list = map {$_ => 1}@list;

my @ordered_nums = grep{$list{$_}}@tokens; 
print "@ordered_nums\n";

__END__
PRINTS:
15 4 13