Microsoft has added to the redirect function in IIS to allow for Query Strings.
In the Redirect to box, enter the domain you wish to move to (no trailing slash), plus $S$Q – for example, http://www.tek-works.com$S$Q
What does this $S$Q do? These are tags that IIS will automatically replace – $S will be replaced with the subdirectory location (such as /shopping/cart.aspx) and $Q will be replaced with the querystring (such as ?id=Blue).
$P Passes parameters that were passed to the URL to the new URL. If the request contains parameters such as http://www.oldsite.com/cart.asp?id=Blue , then $P would represent all the values after the question mark in the URL, example $P would equal id=Blue (no question mark).
$Q Passes the parameters including the question mark. This is the same as $P but includes the question mark or query string. So $P would equal ?id=Blue
$S Passes the matching suffix of the URL to the new URL. If the request is for http://www.oldsite.com/shopping/cart.asp, then $S represents /cart.asp. If the request was for http://www.oldsite.com/shopping then the value of $S would be /shopping
$V Removes the server name from the original request. If the request is for http://www.oldsite.com/shopping/cart.asp then $V would contain everything after the server name, eg: /shopping/cart.asp.
* Wildcard symbol used for replacement. Let’s say you want to redirect all requests for html pages to a single asp page – you could do so in the following way: *;*.htm;page.asp