Pixel position of a data point

Hello all,

I would like to know where the mouse position location of a data point is relative to the graph. Basically, the reverse action of this person's post:

WPF graph display point value on hover

http://forums.ni.com/t5/Measurement-Studio-for-NET/WPF-graph-display-point-value-on-hover/m-p/2433952#M14263

Instead of getting data point,  would like the mouse position. I am overlaying shapes over the graph and would like to know where a specific point in the graph is in pixel location coordinates.

Thank you.