I would like to write a custom elisp function that searches for a few variants of unicode text under a cursor and highlights their occurrences in the currently open file.

For e.g. if my text is helloम् (it ends with bytes U2350+U2381) the function should search a modified version of the text helloं (i.e. hello+U2306) The unicode bytes are always at the end of the word.

I started with a simple elisp function that would print a message if a text that matches my criteria is found and saving the modified string to be searched into a variable:

(defun c-search ()
  "If word under cursor ends with U2350+U2381, search for word+U2306"
  (interactive)
  (if (string-match-p "म्" (thing-at-point 'word))
  (setq z (replace-regexp-in-string "म्$" "ं" (thing-at-point 'word)))
  (message "Should search  %s" z)))

Nothing gets printed when I evaluate this function. However, the following function that searches and replaces the string works fine:

(defun rrx ()
      (interactive)
      (setq z (replace-regexp-in-string "म्$" "ं" (thing-at-point 'word)))
      (message z))

How can I fix function c-search to perform a search for the string saved in variable z?