You do realize the mus command is for only when user is already on the client.
If want to send users to a room from cms while there not on the client then thats easy, all you need to do is add forward id and foraward type to client source.
Edit;
Add something like this in your client source:
PHP Code:
<?php if(isset($_GET['roomid']) and !empty($_GET['roomid'])){ ?>
"forward.type" : "2",
"forward.id" : "<?php echo $core->clean($_GET['roomid']); ?>",
<?php } ?>
Just setup .htaccess or web.config url to /room/id and that extra data client.php?roomid=id
MUS is for when your already in client.