Java mapping for COBOL comp and comp-3 fields

I am invoking DB2 stored procedure created using COBOL from my java application.

input macro (type varchar):

01 SP1-INPUTS.
    05 FIELD-1      PIC X(03).
    05 FIELD-2      PIC S9(09) COMP.
    05 FIELD-3      PIC S9(15)V9(02) COMP-3.
    05 FIELD-3X     REDEFINES  FIELD-3 PIC X(09)

To test the stored procedure, I know only value for FIELD-1. For other fields, to fill the packed portions how many zeros should I put? Please see the code which I wrote and confused in passing dummy values.

String field1="abc";
String field2="000000000"; // 9 zeroes, correct?
String field3="00...0" // should I give 18 zeroes or 9 zeroes?

How much characters totally for the input macro ?