creating lambda an s-expression

i have an s-expression organization non-static common lisp:

(defvar x '(+ 2))

now i wish emanate duty called, evaluates countenance range defined. i've attempted this:

(let ((a 4))
  (lambda () (eval x)))

and

(let ((a 4))
  (eval `(lambda () ,x)))

but both emanate problem: eval weigh formula during tip level, i can't constraint variables contained expression. note i can't put let form eval. there any solution?

edit: there fortitude eval problem, else done?

edit: there doubt accurately i am try do. i am minute compiler. i wish accept an s-expression variables closed verbatim sourroundings where countenance defined. competence indeed improved macro.