How to change the coordinates of the end of the arrow, but not the beginning of the arrow.

Hello, dear friends.

I wrote a macro that extends the arrow shape to the oval.
You can move the oval and the arrow will be redirected to it.
But in my macro-this arrow is inaccurate.
Its "initial coordinate" all the time a little strays.
The" initial coordinate " of the arrow shape must be static and motionless.

How to change the macro, so that as a result of the macro-changed the coordinate of only the end of the arrow, but not the beginning of the arrow?