query-replace, add a "skip to next" in lambda function

I have this function:

(defun fix-mult-punct-before-footnote ()
  "Scope: FOOTNOTE
Description: Fixes repeated/multiple punctuation before the \\footnote macro."
  (interactive)
  ;; "..\footnote{" --> "..\footnote{"
  ;; ".,\footnote{" --> "?\footnote{"
  (query-replace-regexp
   "\\([,.:;!?]\\)\\([,.:;!?]\\)\\(\\\\footnote{\\)"
   ;; REPLACEMENT
   '((lambda (data count)
       (let ((M1 (match-string-no-properties 1))
             (M2 (match-string-no-properties 2)))
         (cond ((string= M1 M2)
                (format "%s%s" M1
                        (regexp-quote (match-string 3))))
               ((not (string= M1 M2))
                (format "%s%s"
                        (char-to-string
                         (read-char-choice
                          (format "The repeated punctuation contains heterogeneous symbols.
Choose which symbol to keep between \"%s\" and \"%s\""
                                  M1 M2)
                          (list (string-to-char M1)
                                (string-to-char M2))))
                        (regexp-quote (match-string 3))))))))
   nil (point-min) (point-max)))

In the read-char-choice point I'd like to add the option to skip the replacement like the n char does normally. For how the function is built now I need to choice the chars in any case and only than I can skip the replacement.

Is it possible?

I'll try to explain better my question.

For how the function is built now when the function processed the string:

.,\footnote{

the second cond case ask me which char, "," or "." use in the replacement using read-char-choice. But if I DON'T want to proceed with the replacement I can't skip it in this point. I need to choose a char and NEXT skip the replacement. I'd like to simplify the process adding a skipping solution in the read-char-choice point.

I mean somthing like:

(defun fix-mult-punct-before-footnote ()
  "Ambito: FOOTNOTE
Descrizione: Corregge la punteggiatura multipla/ripetuta prima della macro \\footnote"
  (interactive)
  ;; "..\footnote{" --> "..\footnote{"
  ;; ".,\footnote{" --> "?\footnote{"
  (query-replace-regexp
   "\\([,.:;!?]\\)\\([,.:;!?]\\)\\(\\\\footnote{\\)"
   ;; REPLACEMENT
   '((lambda (data count)
       (let ((M1 (match-string-no-properties 1))
         (M2 (match-string-no-properties 2)))
     (cond ((string= M1 M2)
        (format "%s%s" M1
            (regexp-quote (match-string 3))))
           ((not (string= M1 M2))
        (format "%s%s"
            (char-to-string
             (let ((user-choice (read-char-choice
                         (format "The repeated punctuation contains heterogeneous symbols.
Choose which symbol to keep between \"%s\" and \"%s\" OR type \"n\" to skip this replacement: "
                             M1 M2)
                         (list (string-to-char M1)
                           (string-to-char M2)
                           ?n))))
               
               (if (equal user-choice ?n)
                   SOMETHING_HERE
                 user-choice)))
            (regexp-quote (match-string 3))))))))
   nil (point-min) (point-max)))