converting Oracle PL/SQL function to DB2 v9

[orausrture]

I am a newbie and really needs some assistance. I have struggled with this code. Any assistantance will be very appreciated. The code is below....

CREATE FUNCTION increment_seria l_1 (p_serial_num VARCHAR(4000) )
RETURNS VARCHAR(4000)
LANGUAGE SQL

BEGIN ATOMIC

DECLARE l_pattern VARCHAR(30) DEFAULT '[A-Z]';

--| l_components OWA_TEXT.VC_ARR ;

--* [200042]"C:\MTK\project s\Unknown1\incr ementnm.src"(29 :16)-(29:30)Unrecogn ized data type: OWA_TEXT.VC_ARR

DECLARE l_components UNKNOWN;

DECLARE l_serial_num_id entif VARCHAR(7);

SET l_serial_num_id entif = p_serial_num;

IF l_serial_num_id entif = '8999999' THEN
SET l_serial_num_id entif = 'A000001';

ELSEIF l_serial_num_id entif = 'A999999' THEN
SET l_serial_num_id entif = 'D000001';

ELSEIF l_serial_num_id entif = 'D999999' THEN
SET l_serial_num_id entif = 'G000000';

ELSEIF l_serial_num_id entif = 'G999999' THEN
SET l_serial_num_id entif = 'J000000';

ELSEIF l_serial_num_id entif = 'J999999' THEN
SET l_serial_num_id entif = 'M000000';

ELSEIF l_serial_num_id entif = 'M999999' THEN
SET l_serial_num_id entif = 'P000001';

ELSEIF l_serial_num_id entif = 'P999999' THEN
SET l_serial_num_id entif = 'T000000';

--| ELSIF OWA_PATTERN.MAT CH(l_serial_num _identif, l_pattern, l_components)
--| THEN

--* [200011]"C:\MTK\project s\Unknown1\incr ementnm.src"(57 :9)-(57:25)Referenc e to unknown object: OWA_PATTERN.MAT CH
--* [200011]"C:\MTK\project s\Unknown1\incr ementnm.src"(57 :60)-(57:71)Referenc e to unknown object: l_components

ELSEIF untranslated predicate. THEN

SET l_serial_num_id entif = ORA.EMPTY_TO_NU LL(COALESCE(SUB STR(l_serial_nu m_identif, 1, 1), '') || COALESCE(ORA.LP AD(ORA.TO_CHAR( ORA.TO_NUMBER(S UBSTR(l_serial_ num_identif, 2)) + 1), 6, '0'), ''));

ELSE
SET l_serial_num_id entif = ORA.LPAD(ORA.TO _CHAR(ORA.TO_NU MBER(l_serial_n um_identif) + 1), 7, '0');

END IF;

RETURN l_serial_num_id entif;

END!