RSS 2.0 using WCF: Adding custom namespace to the rss tag

We have a custom namespace we have for custom elements:

<rss xmlns:blah="http://example.com/">

I'm trying to add this namespace to the rss tag using WCF. Adding an 开发者_JAVA技巧AttributeExtension to the feed puts it in the <channel> element, not the <rss> element.

Beyond string manipulation, how would I go about syndicating RSS 2.0 using WCF with this additional namespace?

It seems to be that the best that can be done is the element.