TRIM Low values X'00

DECLARE StaticValueBlob BLOB CAST('StaticValue' AS BLOB CCSID InputRoot.Properties.CodedCharSetId);

  DECLARE parseOptions INTEGER BITOR(ValidateContentAndValue, ValidateException, ValidateComplete);
        DECLARE vAcctNum CHARACTER;
       
        CREATE LASTCHILD OF Environment.Variables
        DOMAIN 'DFDL';
               
        SET Environment.Variables.DFDL.SUBTREE = InputRoot.DFDL.ROOTRECORD.SUBTREE;
        SET vAcctNum = CAST(ASBITSTREAM(Environment.Variables.DFDL.SUBTREE OPTIONS parseOptions ENCODING InputRoot.MQMD.Encoding  CCSID InputRoot.MQMD.CodedCharSetId TYPE '{}:SUBTREE') AS CHARACTER CCSID InputRoot.MQMD.CodedCharSetId);


copy /Y "C:\Users\govi.reddy\IBM\IIBT10\workspace_dev\BARfiles\MadMoney.bar" "C:\Users\govi.reddy\IBM\IIB\IIB Services\MoneyMovement\Properties\Dev_MoneyMovement.bar"

SELECT ITEM segment.No
        FROM ControlRef.Segments.Segment[] AS segment
        WHERE segment.No = currentSegment;

Working solution:
DECLARE whiteSpace CONSTANT CHARACTER CAST( X'00' AS CHAR CCSID 1208);
TRIM(whiteSpace FROM InRef_RetCode.BE13501_RETURN_CODE)