Need Help : How to make a chat command

[FirstOrder]

So in short, I'm trying to create a super simple script for DarkRP that simple does this:

When a player types [I]/comms *text*[/I] or [I]/radio *text*[/I] it'll display the text like an advert but say Comms instead of advert and it'll be in blue text.

So instead of DarkRP's - [B][Advert] Player Name : Example text[/B]

It'll be [B][Radio] Player Name : Example text[/B]

Basically I'm asking for this to be made more of than a help me because (1) I don' t know crap about LUA in Gmod (2) Im not very good at regular LUA (3) I learn by reading over completed code then using that to make more things in my own way