How about this one Lee, then dump the object again after mtext will edit it.
(defun c:test (/ str p1 p2 txt)
(setq str "Matt W")
(if (and (setq p1 (getpoint "\nSpecify First Corner: "))
(setq p2 (getcorner p1 "\nSpecify Second Corner: "))
(setq txt (entmakex
(list
(cons 0 "MTEXT")
(cons 100 "AcDbEntity")
(cons 100 "AcDbMText")
(cons 10 p1)
(cons 40 (getvar "TEXTSIZE"))
(cons 41 (abs (- (car p2) (car p1))))
(cons 7 (getvar "TEXTSTYLE"))
(cons 1 str)
)
)
)
)
(progn
(vlax-dump-object (vlax-ename->vla-object txt) t)
(command "_.mtedit" txt)
)
)
(princ)
)