use strict;
use warnings;

my @array_code= qw(WE4321 PP7654 8973 7865 TT3422);

my %code_numbers = (
  "4321" =>"XX",
  "7654" => "BB",
  "8973" => ""
);

for (@array_code) {
    my $c = $_;
    $c =~ s/\D//g;
    if (exists $code_numbers{$c}) {
        print "$_ ",  ($code_numbers{$c} || 'IN'), "\n";
    }
}