m pretty sure that this has been asked before, but seriously, EX4100 does not allow any direct connections from outside? Im not talking about the web file manager. I just bought one and the main idea was to connect into it from home network and outside, without putting my PC at risk, by allowing to connect to it externally. As far as i have read, the only option is to share “shares” trough my PC for external mapping. Correct me if i`m wrong.
You could try enabling Webdav on the NAS and access it that way. Try the details at this link :
Don’t forget you will also need to configure a NAT rule on your router to forward the port appropriately as well.