Is it possible to have a normal wordpress site in the root, then Mu in a folder?

Is it possible to have Wordpress running in the root:

http://www.horroruk.com

But have MU run in a folder:

http://www.horroruk.com/blogs

Then have sub-domains created for the main site:

myblog.horroruk.com

I'm asking because the theme I bought for the main Horror UK doesn't work in MU (I've tried everything I can think of), but I'd like the users to have a Horror UK address.