Hi,
sorry for taking longer time to respond.
Our findings are that you unfortunately will not be able to achieve this in the deprecated IBM MQ Series protocol as it does not support setting these properties in this way.
We would highly recommend to switch to the new MQ Native protocol, there you can do what you need by setting these two meta-data properties:
msg.props.JMS_IBM_MsgType = 2
msg.proptypes.JMS_IBM_MsgType = Integer
Regards,
Jan