Clif,
As far i know using JDBC Adapter CustomSQL it does not accept IN statement.
So instead use the JDBC Adapter DynamicSQL for accomplishing this.
Refrace your SQL statement like this in the Dynamic SQL tab:
SELECT CUST_ID FROM CUSTOMER WHERE CUST_ID IN (${CUST_ID})
Now test with your Input: CUST_ID = 0000600010, 0000600011
you will see the results set Output:Cust_Id
HTH,
RMG
#Integration-Server-and-ESB#webMethods#Adapters-and-E-Standards