how to build restreced area?

hi there, although I was seeking at serveral sites, I could not find a solution for my problem. hopefully one of yous has any ides: - project: just a simple client area with restrected acces to folders and their contents. structure: a folder called clients. within this folder the admin creates a folder for every project/client with a start-page (html or php). this page links to other pages (html), images or other files within this folder. the client visits the webpages, is promted to login and is transferred to his directory. the files in theses directories must be protected, that it is not possible to access them by typing the path (although it might be difficult to guess the path). - problem: my provider runs php as cgi-module (thats how it is called, right?) so (for me it seems) that there is no access via the environmental or server vars (sorry I am still new to php), referring to .htaccess. at least these vars do not exist. I am not quite sure how, but I think I could modify the .htaccess files by just writing into them (although I am not sure, if this is possible, if the foler is protected). but anyway, my client wants his clients to login via a user-pwd form. with .htaccess the client would have either to click on a link (so all clients would have to be listed, which is regarding descrition not possible) or the client would have to type the path of his directory, which my client just does not want to. - question: how can I solve this problem? as my client will create all contents within the clients-folders, and theses files will be very different everytime, I cant put everything outside the server-root and create this content by php or use a database. how is this usually done? am I digging in the totally wrong area? thank a lot in advance marcel