url redirects or mod re-writes or something that could replicate that functionallity

ok we are now having problems with our website with google indexing our website as www.cleanalliance.com and cleanalliance.com which has caused alot of our pages to drop into supplemental results

discountasp.net does not have a way of accomplishing this from a global perspective to redirect non-www to www for all of our pages in our website

I can not do it per page.

does anybody know how i could make this happen, anything like a mod-rewrite or htaccess file or there has to be something out there that can make this happen on a windows server with the securities already in place by discountasp.net, or support for an isapi-rewrite tool if we were to purchase or something similar

Thanks!
Alex