Course files in private files folder

Hi! As i prefer some more control over the site's files, I changed the settings of the File content type, changing the upload destination from public to private. In the course's file list it works ok: the file's url is something like http://elearning.site.org/tft/download/file/19 . But when I click on more information for a file, in the file's page the file's url is http://elearning.site.org/system/files/file.ext and this obviously doesn't work. Thanks!