script integration in multisite : is it possible to...

Hello. Just a question about possibility of that :

config wp :

3.0.1 multisite subdomains
domain mapping

the point :

I want to create a specific folder accessible via containing files for a script.
This script has (for the moment) no integration with WP

question :

where this folder can be created ? in blog.dir/blogid/ ?

Will that be ok with the permalink structure ? I mean i need to force auto create the folder on each blod creation ? or can it be created by the script itself in the right place ? Use blog template default to do that ? How WP will react since files in this folder are not WP ? Or shall i chose a folder as images one (files/2010/folder) but in that case le url will not be nice... ?

Technically I can do anything (dedicated), playing with symlink, specific config, etc. The script can even be in another place and just make a link using rewriting but....

not sure to be quite explicite sorry explaining that in english is little hard :slight_frown:

need help on this one