Selecting a single folder to backup (without synching previous files which are online)

Hi all. Apologies if I'm duplicating posts already here - couldn't see anything from my search.

 

Some years ago, I used Dropbox to synch one location on my machine as a backup. Important stuff went into that folder and I let the app keep everything synched. When I got a new machine, I didn't want to download a local copy of everything that had accumulated, so I stopped using the App and just used Dropbox via a web browser as a way to send files to clients.

 

I'd like to continue to store/manage those old files online, but now also create a single folder on my machine which will synch to Dropbox (I will select this within my video software as the location for automatic project backups). When I downloaded the Dropbox app to explore, I found it hard to do this without the app trying to synch my whole machine, or attempt re-synch the previous files. 

 

Can Dropbox be this selective, whilst also leaving the previous files on my Dropbox account where they are (and not trying to download them to my new machine)? Many thanks