[racket] Help needed in writing Macro to transform (lambda (req) ....) to be used in web-server/servlet using auth cookies

Hello again,

I am guessing my problem calls for macro (which is "beyond my pay
scale") and I am hoping this is the right place.

Anyway, after reading this
http://docs.racket-lang.org/web-server/faq.html#(part._.What_special_considerations_are_there_for_security_with_the_.Web_.Server_)

I am led to believe that I will be writing lots of code like this:

(define (some-sensitive-content req)

   (if (user-is-legit req) ;check auth cookie
      (...what have you ...)
      (do-login-and-then-maybe-handle req)))

So here is my first attemp at macro which sorta works:

(define-syntax (guarded-handler stx)
  (syntax-case stx ()
    [(_ name body)
     #'(begin (define (name req)
                (if (user-is-legit req)
                    body
                    (ask-login req))))]))

(guarded-handler gated-content
                 (response/xexpr
                  `(html (head (title "Gated Content"))
                         (body (p "Shhhhhhh")
                               (p
                                (a ([href "/logout "])
                                   "Done"))))))

What I would really like, however, is

(guard (lambda (req) ...)) to transformed to:

(lambda (req)
   (if (user-is-legit req)
      (...what have you ...)
      (do-login-and-then-maybe-handle  req)))

such that I can use it like:

(define (count-dot-com i)
  (count-dot-com
  (send/suspend/dispatch
   (λ (embed/url)
     (response/xexpr
      `(html
        (head (title "Count!"))
        (body (h2 (a ([href ,(embed/url
                              (guard (λ (req)
                                (sub1 i))))])
                     "-"))
...

(define (count-dot-com i)
  (send/suspend/dispatch
   (λ (embed/url)
     (response/xexpr
      `(html
        (head (title "Count!"))
        (body (h2 (a ([href ,(embed/url

                              (guard (λ (req)
                                (count-dot-com (sub1 i))))])
                     "-")
...

in addition to the first case like this:

(define gated-content
 (guard (lambda (req) ...))

Seems simple enough but my naive macros (not shown here to protect my
fragile ego) are failing.
Any help/suggestion is greatly appreciated.

jGc