$sql="select * from my table order by lastname LIMIT 0,5"

if i have this display
lastname
a
b
c
d
e

and i have a data in my table
a b c d e f g h i j k l m n o p

i want to sort only the abcde by desc.what would i do?

what i did is this one
$sql="select * from my table order by lastname sort desc LIMIT 0,5"
this query displays thisponml
i want my display would be edcba