Thanks for the tip @Kiansjet, I was able to find the code that handled sending the message to the RemoteEvent. Sorry it took so long to get back, I was out of town.
For future reference to anyone reading this in the future, the code that handles the RemoteEvent firing for chat messages starts at line 15 of MessageSender.
Compare the “message” string passed into this method to whatever your command symbol is (In my case it was !). If it matches, send a signal to a seperate RemoteEvent that your Command Script on the server listens for, and if it doesn’t match, signal the default RemoteEvent that was there before to send a normal chat message.