How to place a sub page before the domain name (like del.icio.us)

[osprey]

I want to make a page like clown.circus.com. How do I do this? The only way I know how to make sub pages is circus.com/clown, but I want it to be placed before the domain name.

 

[AusQB]

This is done from your web host control panel, if it supports it.