how to put links in the welcome message?

[pitchblack]

I'm going to be starting a space station RPG thing...but i am going to have special decals and prints and stuff.I need to know how to put links in the welcome message.
Like...

Hey there, go [link"here"] to download the needed add ons for my server if you dont want to wait...

[Ad Bot]

[Chrono]

<a:your link without http://>Something here</a>
Example:
<a:www.google.com>Google</a>