How can I override “blog” directory for permalinks?

I have a site cazphoto.co.uk which had an old blog installed on it at “cazphoto.co.uk/blog”. I tried installing a new version (with 3 multisite) as a blog(site) but was told this directory was reserved, so had to choose “photoblog” instead. It works fine. But in order to maintain old permalinks, I’ve had to put rewrite rules in the old /blog/ directory .htaccess file:

(snippet)
RewriteBase /blog/
RewriteRule 20(.*)$ /photoblog/20$1 [R,L]

This also works fine (I don’t have posts older than 2007), for the new installation of photoblog – permalinks are working/redirecting as expected.

OK, now back to the ROOT site. I want to have a NEWS section there (perfect to make with posts from the “root” blog/site). But I can’t make the permalink structure cazphoto.co.uk/news/postpermalink – it’s forcing me to use cazphoto.co.uk/blog/postpermalink which of course breaks – because it’s being redirected to the cazphoto.co.uk/photoblog/postpermalink where the post does not exist!

In the admin screen for the root site, I can set a custom permalink structure – but only BELOW the “blog” directory. How can I change this to “news” instead?

At the moment, I can’t see any way around this. Either my new “news” permalinks will be broken or my old “blog” permalinks will be broken 🙁

Any advice appreciated, thanks!