Sequential counter in SELECT statement

I need to produce a report (using SQL*PLUS) which has a sequential counter defined as the first column of the report. This is easy enough to do using ROWNUM as the first column as long as the result is not sorted. Is it possible to produce this result in a sorted report?

Ex: SELECT sequential_counter_of_some_sort

             ,customer_id
             ,customer_name
         FROM customer_table
        WHERE region   = 'EAST'
     ORDER BY customer_id

The output should be like

ROWNUM CUSTOMER_ID CUSTOMER_NAME

------ ----------- -------------
     1     1000-01 Customer Name
     2     2010-99 Customer Name


     .

     .

 12345     9999-87 Customer Name

Environment is IBM AIX 3.2.5
               ORACLE 7.0.16
               SQL*PLUS 3.1

Thx,

Stephen Miller Received on Sat Mar 15 1997 - 00:00:00 CST