Yes, you've got it...
Here's one I found on CADALYST. It's not the same as the one I used to have, but I get the same end result. It asks for the destination text first, then asks me which sting it should match.
;TIP1286.LSP: SAMETXT.LSP Replace Text (c)1997, Michael W. Becht
(defun C:SAMETXT ()
(setvar "cmdecho" 0)
(setq SAMETXT1 (entget (car (entsel))))
(setq
SAMETXT2 (cdr (assoc 1 SAMETXT1))
)
(setq SAMETXT3 (entget (car (entsel))))
(setq
SAMETXT4 (cdr (assoc 1 SAMETXT3))
)
(setq
SAMETXT1 (subst
(cons 1 SAMETXT4)
(assoc 1 SAMETXT1)
SAMETXT1
)
)
(entmod SAMETXT1)
(princ)
)