SELECT COUNT(*) FROM table WHERE numeric_column < 
  (SELECT numeric_column FROM table WHERE your_criteria)

##</code><code>##

mysql> explain select count(*) FROM faar_homes WHERE price < 80000 \G
*************************** 1. row ***************************
        table: faar_homes
         type: range
possible_keys: price
          key: price
      key_len: 5
          ref: NULL
         rows: 25
        Extra: where used; Using index