Rekordbox playlist query

Hi, 

I am wondering if there is a 'smart' way to add music to my playlists automagicly in the below situation. 

I have 1 folder on my Mac which I add all newly purchased mp3s/flacs to.   

Each time I download new tracks to this folder, I then drag and drop within Rekordbox and overwrite the current playlist of this folder name.  

I will like Rekordbox to auto add all new mp3/flac files from this folder into that playlist without me manually having to drop the folder in each time.

Regards
R