secure document : solution wanted

Hi I am bulding a secure intranet.(php, mysql, apache) I am using a session and Mysql to handel the user accounts. Everythying works fine with that. The client now needs to share word/pdf document with the registered user. I created a secure directory using .htaccess for this purpose and it works as well .... the user are promt to enter a username password. Is there a way to bypass this login box so logged user would be able to access the file, but the directory would still be protected against non-logged user who would know the path and the name the file? I can deal with one .htacces account (username pw) since all the file can be shared with all the users. I was expecting this to work ... http://username:password@www.domain.com/safeDir/Word.doc but it isn't. Any idea what I could do? Thanks