DLink NAS up for external access

I have a Dlink NAS that I am trying to access through the internet. I don't mean through their website, I mean through a mapped window drive. I have already mapped locally and set up a [login to view URL] and associated domain but cant get it to work - the scenario is very similar to the one here [login to view URL] This scope is for someone to work with me remotely to set this up..