Changing Host URL - Jahia 5

Hi,

I am new to Jahia. I am trying to install jahia 5 and create a website that
can be accessed thru internet. When tryin to configure, host URL is by
default taken as localhost. I want to change this so to some address like
www.examplesite.edu/~username, so that it can be accessed from this URL. I
dont see an option anywhere in the wizard to change localhost to this. If
someone could help me out that would be of great help.

Thanks in advance.
Mru.