"pkg_add -r ..." from a url other than the default (using PACKAGESITE, PACKAGEROOT or smth. else)

[Vladik Kozin]

 	What if I'd like the "pkg_add -r" to work exactly the same way as it does by 
default but using an alternative url? Now, let say, there is a url: 
"ftp://fbsd.local/" with the following directory structure 
"pub/unix/FreeBSD/ports/i386/packages-4.8-release/". I'd like to tell 
"pkg_add -r foopackage" and have it installed with all its dependencies from 
the url mentioned above. As far as I understand the PACKAGESITE var specifies 
the exact path to the package, thus if the "/sysutils/foopackage.tgz" depends 
on "/lang/foodep.tgz" then the latter won't be retrieved and the pkg_adding 
process will fail. Probably I need to use the PACKAGEROOT var? But in this 
case the site I intend to use is supposed to have some specific "default 
FreeBSD" structure, isn't it? In my case 
"/FreeBSD/ports/i386/packages-4.8-release/" is a commonly used structure, but 
it is prefixed by "/pub/unix/". 
	Any ideas about how to solve the problem?
	
Best regards.	Vladik Kozin