How to position in SQL with case in order by

[Thunder]

I have this records

....+....1....+....2....+....3....+....4....+..
Type RRN ( File) CONCAT

B 145.352 B000000000145352
B 145.395 B000000000145395
O 145.353 O000000000145353
E 145.392 E000000000145392
E 145.394 E000000000145394

The SQL

SELECT type, RRN(file) , type || LPAD ( RRN(file , 15 ,
'0') FROM ncprec ORDER BY
Case when zetprg = 'B' then '1' when zetprg = 'C' then '2' when
zetprg = 'O' then '3' when zetprg = 'E' then '4' when zetprg = 'P'
then '5' end, RRN(NCPREC)

If i got the key of the 3 record, O000000000145353, how can i get the position?
If i put in the where clase:
type|| LPAD ( RRN(file) , 15 , '0') >='O'||'000000000145353'
it will only return tha line, becouse the next its bigger.