Couple of problems here.
First, you are using the wrong queue. The command server listens on SYSTEM.ADMIN.COMMAND.QUEUE. The queue to which you are sending messages, SYSTEM.ADMIN.COMMAND.EVENT is the queue to which the QMgr puts event messages after executing commands, provided of course that command events are enabled.
The second problem, as Jason mentions, is that the runmqsc processor takes human-readable script and converts it into commands the QMgr can understand. Passing textual commands directly to the command server won't work.
Typically we do what you want by passing the commands to runmqsc directly such as...
echo DISPLAY QMGR ALL | runmqsc MYQMGRNAME
If you require the ability to do this as a client, then you want to either download SupportPac MO72, or head over to MQ Gem and pick up a copy of MQSCX. Either of these will accept the command above on a local queue manager, and both can also be supplied with MQ Channel params and connect to a remote QMgr.
In addition to this basic functionality, the MQSCX product also has its own internal script parsing and execution. Suppose, for instance, that you want to do something depending on the command level of the QMgr.
Using runmqsc you could issue the command above, filter the resulting 2-column output through grep, awk, or similar, then capture the final output into a variable. You might need to do this multiple times to capture multiple values, invoking a new runmqsc each time and parsing the output in your script. You must then generate the string for the actual command you wanted to run when you started all this, and pass it to another invocation of runmqsc.
Alternatively, MQSCX lets you issue the DISPLAY command, then reference the resulting values directly by name. For example, you can pass MQSCX a couple lines of script telling it to inquire on the QMgr and then take a conditional action based on the command version, all without ever having to drop back into shell, bat or Perl script.
Full disclosure, I do not work for or get a commission from MQ Gem. I just don't like to beat my head against the wall writing 100 lines of code where 2 will do. If you do any amount of MQSC scripting, the ROI on MQSCX is measured in minutes. And it happens to be 100% on-topic as an answer to this question.
