Right BDL, there are two ways to do it.
1. create a name script which i have no idea how to do! lol
2. do what i do.
Open microsoft word. type in ~. AND CHANGE THE COLOUR TO WHITE(that is important). Once you have changed the colour u cant see the flame because of the background but that doesnt matter. Now copy the white ~.
go on server and type in your name in console and paste the flame (to paste press CTRL and V at same time).
You should get a " symbol (this means its correct). Once you press enter, this " symbol will change to ~.
Its very easy.