Because you are trying to "map" search-friendly URL requests to script filepaths+query_strings on your server, this is an internal server-side URL-to-filepath rewrite, not a external client-side URL-to-URL redirect.
See the thread
Changing Dynamic URLs to Static URLs [webmasterworld.com] in our Apache Forum Library and the resources cited in our Apache Forum Charter to get started. Your application is simpler than the example in that thread, so you can likely simplify the example code quite a bit.
Other related-topic threads should be findable with a site search for "rewrite static URL dynamic filepath" and similar phrases.
Beware of the commonly-encountered problem with putting variables into your URL-path: It is the browser that resolves relative links on page to the canonical full URL that it must request. Therefore, all links on your pages must be server-relative or canonical. For a concrete example, you must use the forms <img src
="/images/logo.gif"> or <img src="http://example.com/images/log.gif"> and not <img src
="images/logo.gif"> or <img src
="../images/logo.gif"> for images, CSS files, and external JavaScript files referenced in your HTML.
Jim