ISSUE: Blogger and Domain hosted at plus.net

[#1]

Hello
I have a new blog which I am just starting to write on and what I would like to do is is point a subdomain of a domain hosted at plusnet.
For example i have:
www.domain.com ; =  working correctly and pointing to plusnet hosting
domain.com  =  working correctly and pointing to plusnet hosting
Next I would like to add:
blog.domain.com  : This needs to point ghs.google.com
I cannot seem to work out what I am supposed to put in the right field, left field cname, a record etc!!! Also there seems to be an important . (full stop) that needs to go somewhere but I am not sure where!!!
All help will be most appreciated.
Thanks
G

[#2]

This should just work with:
Left hand side: blog
Priority: blank
Type: CNAME
Right hand side: ghs.google.com.
The "." on the end of the ghs.google.com is very important, otherwise you'll end up with it pointing to ghs.google.com.domain.com.
HTH