533527 Mod rewrite for New URLs

Hi, I have a site that has dynamically generated pages with pages like: [login to view URL] & [login to view URL] What I need is for URL's to be re-written so they look like this: [login to view URL] & [login to view URL] Some points to note. 1. The site is hosted on a linux server so this can be done in the .htaccess. 2. It is a custom made site so existing oscommerce contributions probably won't work 3. The rewrite rule must work both ways and send people using the current URL address for the old links to the new seo friendly URL's. 4. When in place it should prevent warning if users decide to call up modified URL's (for example, [login to view URL]'enterdodgycode' will give a warning and error. As pages are dynamic this has to occur for all pages using a wildcard rule (e.g. not just current products but .php?id=1 to .php?id=999999 etc) 5. Metatags are dynamic and stored in the database. If possible I would like to avoid having to rewrite these tags onto the new pages. If you have any questions please let me know and thank you for your bids.