;Specifically changes integers in "..MH #?" strings by 'value'.  (uses UINT )
(defun c:nmhn (/ mhstr)
  (setq mhni (uint 1 "" "Number to add to existing MH #?" mhni))
  (while
    (setq mhte (entget(car(entsel "\nSelect manhole # text"))))
    (setq mhstr (assoc 1 mhte))
  (while
    (not (eq "MH" (substr (cdr mhstr) 7 2)))
    (progn
      (setq mhte (entget(car(entsel "\nSelect manhole # text"))))
      (setq mhstr (assoc 1 mhte))
    );progn
  );while
  (setq mhnum (+ mhni(atoi(substr(cdr mhstr) 10))))
  (setq mhstr (strcat(substr(cdr mhstr) 1 9)(rtos mhnum 2 0)))
    (progn
      (setq mhte
      (subst (cons 1 mhstr)
             (assoc 1 mhte)
             mhte
      );subst
      );setq
      (entmod mhte)
    );progn
  );while
);defun