my @array = qw(Art bob joe andy willy Andrew john Archie);
foreach(sort {substr($a,1) cmp substr($b,1)} grep /^A/, @array){
    print "$_\n";
}

__OUTPUT__
Andrew
Archie
Art

##</code><code>##

foreach(sort {substr($a,1) cmp substr($b,1)} grep {substr($_,0,1) eq 'A'} @array)