Add Shape (arrow) to an Excel Chart AND auto re-position

Hi -

I have a Combo Chart (primary series is a scatter graph; secondary series is a line graph). The Secondary Axis is a straight line (single $ Amount). I've manually added a Shape called "Left Arrow", and have added some text (linked to a cell) that pertains to the Secondary Axis. The shape is on the right side of the graph where the secondary vertical axis would be.

Question is: Using VBA, how can I auto adjust the position of the arrow shape to align with the Secondary Axis that will change each time I update the graph? I have tried to use the .Top alignment for the arrow shape via VBA, but I can't seem to match this ".Top" with anything on the Secondary Axis.

As mentioned, the Secondary Axis can & probably will change with each refresh, so, if using VBA I can determine the Secondary Line amount, can I use that to help the arrow shape to find the right position?

Anybody have an example / code?

Any help is greatly appreciated!

thanks,
GRC