Is there any way to list the media files only if they are not on the hard drive, so i won┤t get that songs listed twice with different path?
Something like Path1 and Path2 for the same song?
That's exactly what Cache is supposed to be used for. You can have songs on CD-ROMs only and when you want to have them accessible on HD, just cache them and they will be on both media but just with a single entry in the database.