Thank you both for your time and fast (!) answers.
@ RealAct: Yes. I did try leave both user and password [empty] and a real user and password [empty] --> that didn’t work out
@ Tony: This is kind of odd. I tried your “net use etc” and (ohh it seems like its is case sensitive) … With my “user-share” (the one default created per user) it came up with “OK command executed”. Nothing else. It was not in explorer. However I did manually connect to it via explorer (add network storage etc). That went well.
Inspired by my luck (and your advice) I tried my other share (the “common share for all users”, not public but a mediashare created so all my users can access the same media-files) … no luck. Both on command-line and the long way via Explorer “add …”
Both ways I get the (dreaded?) please sign in to the domain.
The “Domæne” is of course domain, and that (REMOTE) is my home workgroup, I do not have a domain-server.
The MyCloud is on another workgroup (“NONAME”). It doesn’t make any difference if I set MyCloud to “Remote”.
I cannot help but thinking that it is a windows “feature” …