#! perl -slw
use strict;

my %a=( AA=>'Y', BB=>'Y', CC=>'Y', DD=>'Y', EE=>'Y', FF=>'Y' );
my @a1=('AA','DD','EE');
my @a2=('AA','BB','CC','FF');

my @a = sort keys %a;
my %a1; @a1{ @a1 } = ();
my %a2; @a2{ @a2 } = ();

print join ',', map{ exists $a1{ $_ } ? $_ : '##' } @a;
print join ',', map{ exists $a2{ $_ } ? $_ : '##' } @a;

__END__
[11:44:17.92] P:\test>413151
AA,##,##,DD,EE,##
AA,BB,CC,##,##,FF