Synch files/folders on PC

Okay, I have done a little searching and have not come across an answer, but if there is one, please direct me to it. I am trying to find a way to synchronize files within a folder on my PC with the media card on my BB. Say, a subfolder within My Documents. Then it would notice when I edited a file either on my PH or BB and update both with the most recent version (similar to what DM does with your calendar/contacts/tasks). Is there something within DM or Media Sync that I am just missing or is there a separate add on I need to download (similar to the way FlexWallet works). I would be willing to pay a small amount for the software.

Thanks for your help!