Here you go. It will change the pointing point to 0,0,0 for anno leaders, and non-anno leaders, at least it did in my test drawing that I posted. Time for lunch, so I'll answer questions after, if you have any.
(defun c:Test (/ Sel MnData data)
(setq Sel (entsel "\n Select mleader to change it's arrow point to 0,0: "))
(setq MnData (entget (car Sel)))
(if (setq data (member '(102 . "{ACAD_XDICTIONARY") MnData))
(progn
(print "dict")
(setq data (entget (cdr (assoc 360 data))))
(if (setq data (member '(3 . "AcDbContextDataManager") data))
(progn
(print "man")
(setq data (entget (cdr (assoc 360 data))))
(if (setq data (member '(3 . "ACDB_ANNOTATIONSCALES") data))
(progn
(print "scales")
(foreach i (entget (cdr (assoc 350 data)))
(if (equal (car i) 350)
(progn
(setq data (entget (cdr i)))
(entmod (subst '(10 0. 0. 0.) (assoc 10 (member '(304 . "LEADER_LINE{") data)) data))
)
)
)
)
)
)
)
)
)
(entmod (subst '(10 0. 0. 0.) (assoc 10 (member '(304 . "LEADER_LINE{") MnData)) MnData))
(princ)
)