Detect Cell Address Of Cell Directly Under Mouse Pointer

I've a sheet that presents the profitability of sales locations in a geographic layout (similar to Tables in a restaurant), each sales location is a cell, with roughly 1,600 locations presented. Each location is colour coded based on performance / measure, in a basic thermographic way [e.g. dark blue for very poor, solid red for high performance] with users being able to change metrics and re-colour cells accordingly.

The sheet is already information rich, but I'm wanting to detect the cell address directly under the pointer and populate a text box or other cell based on the value in the cell directly below the mouse pointer.

My question is; Is there a simple way of detecting the mouse position on the XL Grid? nb. Want to avoid having to activate cell beneath pointer.