The sub-domain name is generic so no problem there.
I realize I could do this as you explain, but the problem is restoring my original blog to the new blog location (blog.new-domain.com). I have already tried this with the wordpress import tool and it totally wrecks the site. I don’t want the blog I am converting to be the MAIN multisite, rather a sub-domain.
For that reason I was hoping there is someway to start from ‘blog.new-domain.com’ as the MAIN Multisite and somehow setup a ‘new-domain.com’ site and change that to be the MAIN multisite while keeping the site ‘blog.new-domain.com’.