Aha, I see, I've confused the 'A' with DNS. That's a fundamental error. I've got some reading to do. Yup, that works. Thanks very much for your help.
There is however one other tiny matter, which I'm confused about. This is a Joomla site. The 'absolute path' for the site I have set to mineralconsulting.com in the config.ini file, 'cos that's the name of the containing directory, so that works, but www.mineralconsulting.com as yet does not.
I've got the domain config at DH set to accept with 'www' or without and added two 'A' entries over at Arsys (one with and one without) with the same 'correct' IP. Is this the right way to do this, or do I have to accept one or the other?
I'm off to do some reading, any other help most gratefully received. Thanks again.
Erm, I've found this:
Which suggests that the problem might resolve itself if I wait for propagation. Still not sure if I should use two 'A' entries though...
/_/_ / (
( /( /)(/__)())(