*NEWBIE* pointing domain from username.plus.com to new CCGI Wordpress on Plusnet

[#1]

Hi All,
Sorry if this question is very basic but I'm new at this domain stuff.
I've currently got a .co.uk domain hosted on plusnet, and use this for my email domain name and to point to a website landing page on www.username.plus.com  through the "default" domain hosting settings on the member centre configuration for domain names (i.e. it maps my .co.uk address directly onto my username.plus.com address).
I'm now trying to set up a wordpress website on the ccgi.username.plus.com side, and once this is ready I would like to point my domain name to the wordpress site, whilst ensuring my email settings also still fall under my domain name.
How on earth do I do this through configuration in the member's centre domain names section ?
I'm sure it's pretty simple but, as I said, I'm a bit of a numptie at all this !
thanks for any help
Dave

[#2]

Some way down the line yet but I think getting the DNS pointers for a domain and www.domain redirected to ccgi needs to be requested on a ticket. I believe this is so because the existing records do not appear in our control panel.