I'm really surprised that there isn't such a command already or maybe I just missed it, if that's the case please let me know. And please add the command to the controls as well so we can bind it to a key.

I'm talking about a command to say something in the system chat.

I think there is a plugin out there that does this. You can use the api to make your own as well.

http://www.vo-wiki.com/racecar2/index.php/API_SendChat

Ugh... What's an API and how do I use it? >->

Do you know the name of the plugin? I would also be interested in a command that I could bind to a key to talk in system chat.

From this post: https://www.vendetta-online.com/x/msgboard/1/17100#216247

Credit to slime73 for the Lua witchcraft for this:

1) Create a folder inside addons/ named "SystemChat".
2) Create a file named "main.lua" inside SystemChat. This file should contain the following:

RegisterUserCommand("System:", function(_,m) SendChat(table.concat(m," "), "SYSTEM") end)
RegisterUserCommand("say_system", function(_,m) SendChat(table.concat(m," "), "SYSTEM") end)

Now you can bind keys to either System: or say_system (System: will look more like the other chat commands while flying around).

edit
For the lazy, I uploaded it to http://www.voupr.com/plugin.php?name=saysystemchat

you've just floated into my heart. Thanks!

Thanks We All Float!