Redirecting wordpress.com custom domain to self-hosted wordpress at subdomain

I have looked around and cannot find a solution that comes close to addressing my issue. Here’s the rundown.

I started a blog over at wordpress.com, I added a custom domain through wordpress.com but decided after a while that I wanted to host the blog myself for various reasons. I worked something out with a friend who would install it on his server and host it as a subdomain of his own website. I thought it would be simple enough to just change the nameservers at wordpress.com to point to the bluehost nameservers but now the domain points to a generic page.

I’m wondering if there is a simple solution to redirect the domain at wordpress.com to a subdomain.