Step 1.
Finding the function to call commands and how they are evaluated.
Looking at the main Cmdr module script I see this:
-- Handle command invocations from the clients.
Cmdr.RemoteFunction.OnServerInvoke = function (player, text, options)
return Cmdr.Dispatcher:EvaluateAndRun(text, player, options)
end
I then think, how can I use this to fire events.
Step 2.
Firing events from the client is done via the UI, so, why not just fire them when you do basic chat commands.
Chat commands are simple to set up and there are many sources out there on dev forum.
So I recommend looking into them.
Step 3.
After you have set up a basic chat command that works and you have tested it, I really just suggest looking into how the script above handles talking to the client.
You may have to make your own public event under ReplicatedStorage and modify how Cmdrs communicates, however, this may ruin Cmdrs safety and it can be risky.
But that is how I would go about looking into doing it.