newbie case sensitive question

Greg,

why do you need to check the URIs? If the requested ASP does not exist on the origin server (node), the server will issue "bye, bye" (404 Not Found) response on it's own 🙂 If there are some ASPs on the server that you do not want to be exposed at all, then I'd suggest to remove them.

Having said that, you rule might look like this (assuming that the ".asp" extension is always lowercase and also URIs are in the root):

rule name_check {
   if(substr(http_uri, 30) == "" and http_uri ends_with ".asp" and substr(http_uri, 1, '.') matches_regex "^[a-zA-Z0-9]+$") {
       use pool some_pool
    } else {
       redirect to "http://betterlucknexttime.com"
    }
}