Lambda the Ultimate

I am looking at a way to implement Resume in a CPS-based intermediate language. Resume allows to try again a calculation with a different value.

If I mark the resume value with ^retry I want to do:

1 + ^retry 8  (* 9 *)
retry 5       (* 6 *)

In CPS, 1 + 8 may look like:

lambda (k) (k (+ 1 8))

Then I will extract the continuation around "8" to save it in a "retry" variable:

lambda (k) ((lambda (n) (k (+ 1 n))) 8)
lambda (k) ((lambda (k') (k' 8)) (lambda (n) (k (+ 1 n))))
(* save continuation *)
lambda (k) ((lambda (k') (do ((set! retry k') (k' 8)))) (lambda (n) (k (+ 1 n))))

I could do the same transformation for an arbitrary nested variable. What I do not like is that I use a "global" variable retry which I set!, but the alternative is to pass it around as a function parameter-- not very convenient.

Is my reasoning correct? Is there a better way?