@sorted = sort by_num_then_letter @unsorted;

sub by_num_then_letter
{
   my $a_region = lc ($a->region_name); 
   my $b_region = lc ($b->region_name);

   my $a_non_digit = ($a_region =~ /\D/); 
   my $b_non_digit = ($b_region =~ /\D/);

   if ($a_non_digit and $b_non_digit)
   {
        $a_region cmp $b_region  
   }
   elsif (!$a_non_digit and !$b_non_digit)
   {
        $a_region <=> $b_region 
   }
   elsif ($a_non_digit) #digit only thing is always less than
   {
           1;    # b > a (reverse 1 and -1 if I got this wrong)
   }
   else
   {
          -1;    # b<a
   }
}