johngg@abouriou:~/perl/Monks$ perl -Mstrict -Mwarnings -E '
my @list = do {
   no warnings qw{ qw };
   qw{ 1,cat 2,dog, 22,mouse frog 11,eel 001,elk horse 002,bear 13,mink };
   };
say for
   map { unpack q{x54A50} }
   sort
   map { pack q{NA50A50}, ( m{^(\d+),(\S+)} ? ( $1, $2 ) : ( 0, q{} ) ), $_ }
   @list;'
frog
horse
1,cat
001,elk
002,bear
2,dog,
11,eel
13,mink
22,mouse