How to write a program (where to dig, where to start) for a poppy with an action function when you hover over a certain area of ​​the screen?

Question

Programming

I want to write a poppy program to adjust the system volume with the mouse wheel, but only when the mouse is on the taskbar at the top. I could not find material on the net, I am looking for material on this issue

Answer 1

And that in the Mac it is no longer adjustable with a wheel?
Now I checked it on Win8, it's easy to adjust ...
And you need to search in Google, type in "Programming for Mac for Beginners".

Answer 2

You see, I want to adjust the mouse wheel not only by clicking on the sound icon, but when hovering over any place on the taskbar at all. In my opinion it will be very convenient. I am newbie. Googled, but found only examples of application programs and it's not entirely clear how to interpret this for my case