controling your url

hello

can somebody explain to me how this works?? an adress like....

http://je.suis.perdu.com/

i presume the name bought here is 'perdu.com' however how do you get to control the server so that you can put words before the 'perdu' with a dot instead of the www???

any help much appreciated because i dont know where/what to search for on help on this!

a+
gar

Offtopic, should be either in dns or beginner forum. That 'feature' is called "sub domain" - interchangable with "virtual host" - and is set up in serve configuration.