306985 htacess and 301 redirect

Hi, I've moved a client's site onto a new CMS and want to use redirect 301s to point the old URLs to the new addresses. The problem is, the old URLs have a ?, and the browser ignores everything after that point. From what I've read, there is a way of using mod_rewrite to solve this but I can't get my head around the solution so am looking for help. Alternative solutions welcomed.