(defmacro xyz (a)
  (flet ((q (b)
       (etypecase b
         (string (list b :m))
         (symbol (list (symbol-name b) :z)))))
    `(list 'f ,@(q a))))

(defun abc (f)
  `(g ,@(funcall f)))

(xyz 'a)
(xyz "b")
(abc #'(lambda () (list 4 5 6)))