short form:
1) deploy to web from the editor, this will give you an www folder containing the structure needed for the web
2) in the FTP, make a new folder with whatever name you want to appear in the adress line of the browser
3) create a link to exactly that folder on your site
4) copy the contents of the www folder to the new folder by using FTP - it is important that the entire directory structure needs to be the same, just what is inside the www folder locally has to go into the new folder on the FTP access (do not create the www folder online, that is a placeholder name)
that's all - assuming that you have full FTP access and that the website can handle the link to the folder.