User defined function which can be called in Stored Procedure

I have a stored procedure as pasted here. This takes divNo as a parameter which is comma separated string like (81,75,68).
I need to parse this string and get the individual values 81,75 etc in a temporary table through a user defined function and call this function in a stored procedure and fire a select query like  s.DIVISION_CD IN (divNo).
Since s.DIVISION_CD is integer column hence I cannot use directly s.DIVISION_CD IN (divNo) .
It gives datatype incompatible problem.
Also this same function will be called in the place of (SELECT NumericRows FROM   TABLE (StringToNumber(divNo) ) t ) in the stored procedure which takes a left outer join with the above query.
Please note that I need this function and its usage in Stored Procedure strictly in DB2 and not oracle.
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CREATE PROCEDURE "AHRTLP"."GET_COMPANIES" ( IN stateCd CHARACTER(2),
                                          IN coverageCd CHARACTER(3),
                                        IN admittedIn CHARACTER(1),
                                        IN productCd CHARACTER(5) ,
                                        IN divNo varchar(2000),
                                        IN effectiveDt DATE )

    DYNAMIC RESULT SETS 1
------------------------------------------------------------------------
-- SQL Stored Procedure
    -- stateCd
    -- coverageCd
    -- admittedIn
    -- productCd
    -- divNo
    -- effectiveDt
------------------------------------------------------------------------
P1: BEGIN
    -- Declare cursor
    DECLARE cursor1 CURSOR WITH RETURN FOR
   select a.PRODUCT_CD,a.ADMITTED_IN,a.COMPANY_NO,a.COMPANY_NM,ISSUING_CO_NO,a.ORDER_SQN,(case when SBSTT_MAJOR_CLASS_CD  is null then a.MAJOR_CLASS_CD else SBSTT_MAJOR_CLASS_CD END )MAJOR_CLASS_CD,a.NumericRows from (

   select i.PRODUCT_CD,i.ADMITTED_IN,i.COMPANY_NO,c.COMPANY_NM,c.ISSUING_CO_NO,i.ORDER_SQN,m.MAJOR_CLASS_CD MAJOR_CLASS_CD,m.STATE_CD,d.NumericRows
   from AHRTLP.TPPS_PRODUCT_MCC m,AHRTLP.TPROD_ISSUING_CO i,AHRTLP.TANNUAL_STMT_CO c,
 (SELECT NumericRows FROM   TABLE ( "AHRTLP"."StringToNumber"(divNo) ) t ) d
   where m.PPS_PRODUCT_CD = coalesce(productCd,m.PPS_PRODUCT_CD)
 and
 m.STATE_CD = coalesce(stateCd,m.STATE_CD)
   and m.EFFECTIVE_DT <= effectiveDt
   and m.EXPIRATION_DT >= effectiveDt
   and m.COVERAGE_TYPE_CD = coalesce(coverageCd,m.COVERAGE_TYPE_CD)
   and i.PRODUCT_CD = m.PPS_PRODUCT_CD
   and i.STATE_CD = m.STATE_CD
   and i.ADMITTED_IN=  coalesce(admittedIn,i.ADMITTED_IN)
   and i.COMPANY_NO = c.company_no
) a
   left outer join AHRTLP.TSUBSTITUTE_MJC s
   on a.COMPANY_NO = s.COMPANY_NO
   and a.STATE_CD = s.STATE_CD
   and s.EFFECTIVE_DT <= effectiveDt
   and s.EXPIRATION_DT >= effectiveDt
   and s.DIVISION_CD IN (divNo)
   and s.MAJOR_CLASS_CD = a.MAJOR_CLASS_CD
 order by a.PRODUCT_CD,a.ADMITTED_IN,a.COMPANY_NO;

    -- Cursor left open for client application
    OPEN cursor1;
END P1Start Free Trial