redirect rule for http://www.example.com/http://www.example.com

Question

Checking web master tools I've found a third party has incorrectly linked to my site with a url following this pattern:

http://www.example.com/http://www.example.com

I added in a rule to my htaccess file, however I get a 403 forbidden response.

RewriteRule ^http://www.example.com / [r=301,l,nc]

How should I go about resolving this rule?

Thanks