So I've been battling a bit with this all again today!
Turns out WIX does not support phpbb, hence the forum I have installed is somewhat sub-optimal - this is because, basically there is an inability to assign roles and permissions for differing hierarchies within the forum.
So... that said, I managed to find a neat little <html thingy> that could point to sub-domain where the forum could sit. Magic.
Turns out WIX only supports https and not just http, which complicates things somewhat, I think.
All that said and done, I will get there eventually.
Really pleased with the look and feel of the site - it looks pretty tidy, and I just want to get the last few things licked - ie. finding a host, and somewhere to plonk the forum.
Once that is sorted, I will have to nip through the side, amend all the links to make sure they point to the correct page and so on... and then we will be good to go!
All getting rather exciting now!