[xwiki-users] conditional redirect after login

Hi, We would like to, conditionally, redirect users who log in to their profile page. (in our case; XWiki.<username>) The condition is: User is not in ANY OTHER GROUP then XWikiAllGroup. How can I do this most elegantly, modifying as little as possible of the standard pages that come with a distribution of XWIKI Gerritjan Koekkoek