$ perl '-M5;%h=map{$_,++$i}split//,"ARNDBCEQZGHILKMFPSTWYV"' -alpe '
  ($_=$F[0])=~s/[A-Z]/$h{$&} /g'
$ perl -alpe '
  ($_=$F[0])=~s/[A-Z]/(index("ARNDBCEQZGHILKMFPSTWYV",$&)+1)." "/ge'