As far as I know it doesn't work (as I told you). I've never seen it working.
If I had to guess how to make it work, it would be through ASM and XML.
Code:
<STR id="CMD_NAME_3">report</STR>
<STR id="CMD_USAGE_3">/report</STR>
<STR id="CMD_HELP_3">Report details of the chat</STR>
<STR id="CMD_ALIAS_3_1">112</STR>
<STR id="CMD_ALIAS_3_2"></STR>
As most of the commands in the XML's are called from the runnable, im guessing this code was either unfinished, or not made.
So probably either find the code, or make a code cave calling it and making it work like the others.