Find & Replace

I'm sorry to be asking this as I should be able to do it myself and indeed have routines that ALMOST do what I need, but as usual I am in a hurry.

Has anybody got a routine that will replace the 2nd character in a (select by mouse) string with "Z"?

That is I need to select the text GS-1330/1A and have it updated to GZ-1330/1A

-------------------------------

I've now read what I need to do properly and I should be asking for the 2nd letter to become a Y

Wouldn't you be able to do this using the normal FIND command and wildcards?

not easily as the first letter isn't fixed. I have done one sheet (out of many) with find A?- replace with AY- but I have a complete alphabet to go through.

Searching for ??- gives me ?Y-

(defun c:test (/ ss)
 (if (setq ss (ssget "_:L" '((0 . "MTEXT,TEXT"))))
   ((lambda (i / ent s)
      (while (setq e (ssname ss (setq i (1+ i))))
        (setq s (cdr (assoc 1 (setq ent (entget e)))))
        (entmod (subst (cons 1 (strcat (substr s 1 1) "Y" (substr s 3))) (cons 1 s) ent))
      )
    )
     -1
   )
 )
 (princ)
)

(defun c:test (/ ss replace)
 (if (and (setq ss (ssget "_:L" '((0 . "MTEXT,TEXT"))))
          (/= "" (setq replace (getstring "\nSpecify replacement letter: ")))
     )
   ((lambda (i / ent s)
      (while (setq e (ssname ss (setq i (1+ i))))
        (setq s (cdr (assoc 1 (setq ent (entget e)))))
        (entmod (subst (cons 1 (strcat (substr s 1 1) replace (substr s 3))) (cons 1 s) ent))
      )
    )
     -1
   )
 )
 (princ)
)

thanks Alan, I'll try it on Monday but the problem has gone away (from me). I went home early unwell yesterday and left the problem with somebody else Should be done by Monday!