Updating single row/column in table A with values from single column but multiple rows in table B

I am trying to construct an UPDATE statement to update a single column in a single row in table A with concatenated values from a single column in multiple rows in table B. In googling the subject, I have found a concept in MYSQL called Group_Concat that seems to accomplish that task, although I only found examples where it was used in Select statements, not Update statements. I looked in the DB2 for I SQL reference and could find nothing about this concept. Is there a way to accomplish this using DB2 for I SQL?? Below is one of my attempts to try to use the Group Concat:
　
UPDATE MLPFLKSCD A SET A. FSADIN = GROUP_CONCAT(SELECT
B.FXDATA FROM MLPFLOCKAD B WHERE A.FSCMP=B.FXCMP
AND A.FSLOC=B.FXLOC AND A.FSFARMNO=B.FXFARMNO AND
A.FSBARNID=B.FXBARNID AND A.FSYEAR=B.FXYEAR AND A.FSNUM=B.FXNUM
AND A.FSPENID=B.FXPENID AND A.FSSEX=B.FXSEX AND A.FSTSLT=B.FXTSLT
AND A.FSSTDT=B.FXSDAT)
 
MLPFLKSCD is Table A and MLPFLOCKAD is table B
Thanks for your help in advance,
 
Fred