If it's a flatfile database, then either convert it to SQLite or Pg or use DBD::CSV or DBD::AnyData directly on the flatfile. With those two DBDS you can use "SELECT $cols FROM $table WHERE $field LIKE 'A%' ORDER BY $field" on a flatfile. If you don't care about the case of the letter use UPPER($field), otherwise it will find only "Ant", not "ant".