WebSphere MQ, WebSphere MQ Everyplace, and SCADA messages include an MQMD header. You can use a JavaCompute node to refer to the fields within the MQMD, and to update them.
public void addMqmd(MbMessage msg) throws MbException { MbElement root = msg.getRootElement(); // create a top level 'parser' element with parser class name MbElement mqmd = root.createElementAsFirstChild("MQHMD"); // specify next parser in chain mqmd.createElementAsFirstChild(MbElement.TYPE_NAME_VALUE, "Format", "XMLNS"); }