Rewrite help - Domain to subfolder/subblog

Blog are hosted at http://www.server-a.com/blogs/1. How do I forward requests from http://www.server-b.com to http://www.server-a.com/blogs/1. Already have a vhost entry that forwards users to http://www.server-a.com/blogs/. Forwarding users to http://www.server-a.com/blogs/1 causes an internal server error.

Thank you.