Falsche Zeichen in einem DB-Feld per SQL finden

[omata]

SQL-Code:

SET TERM ^ ;
CREATE OR ALTER PROCEDURE CLEARNUMERIC (
  INPUTSTR Varchar(100)
)
RETURNS (Result Varchar(100)) AS
BEGIN
  Result = '';
  WHILE (InputStr <> '') DO BEGIN
    IF ('0123456789' NOT LIKE '%' || SUBSTRING(InputStr FROM 1 FOR 1) || '%') THEN 
    BEGIN
      Result = Result || SUBSTRING(InputStr FROM 1 FOR 1);
    END
    InputStr = SUBSTRING(InputStr FROM 2);
  END
  SUSPEND;
END^
SET TERM ; ^

SQL-Code:

SELECT *
FROM IDOC_REAL
WHERE (SELECT result FROM CLEARNUMERIC(ScanCode)) <> 'F'