It seems likely that this is an obvious question, but I'm having trouble tracking down any useful information. Normally when accessing files in a particular directory on a server, I'm able to create a virtual host, assign a domain, root directory location, etc -- however am in a situation where I have server space and need to access files with only a hostname. Is this possible?

For example, let's say the hostname is 123hostname.com, and the file I want access to is in /home/sub-directory/filename.php. How do I get at it via a browser?

I've tried:
http://123hostname.com/home/sub-directory/filename.php

...and some other variations on that theme (that I can't post because new users are restricted to one link in messages). But generally stuck. Any help -- even if it's just to let me know that this isn't possible without some additional configuration -- would be great. Thank you!