I've forgotten the commands you can use while looking at your dedicated server screen.

I mostly need to command needed to talk because when I can't be in the room playing I'd like to be in contact with the players in there

commands are in the soldat manual.
and to speak /say [your text here]

You cannot enter commands directly into the dedicated server "screen", you must use an admin client to connect to the server and then execute the commands here.

The question has been answered, so I'm locking both your topics about this just to make sure you're aware that you are now allowed to cross-post (post one topic in multiple forums"