Download & Upload of .doc files


We are developing an e-Learning Platform and the key Technic for the skills improvement is the exchange of files between the instructor (anonym) and the client (anonym). It means that during the course, the client will send a DOC file to the instructor, he will review and return the reviewed file to the client. I already tried the solutions proposed by the CoursePress Pro, like the Download and Upload Module, but it seems not to work so well with files exchange during a course. And it accepts just .ZIP, .PDF. I want something simpler, where the client just sends his text .doc and receive the files during the course.
Do you have a solution, please?

Thanks a lot,