Setting directory privileges + com?

Is is possible to create a directory under windows 2000, turn network-sharing on, but only for certain users, with something like com, winapi?

Maybe I should tell you about the whole situation, I am building a Project Management system for a company, the main framework is programmed with php, the company's employees have a username and password and they can easily browse through files that belong to their projects. BUT the company ensists that files can be uploaded with Windows Explorer on the local network. So when a new project is created and users are given the privileges to browse through that project online and with windows explorer. So I was thinking if I could build a console application which php executes that would set these privileges.

Any Ideas?