How to draw over buttons, captions.... on panel?

Question

C++ / C#

There is a panel, it has a lot of buttons and inscriptions (label). How to draw on top of all these buttons and labels? How to draw in the foreground, draw on buttons and labels. Someone didn’t understand?) Look at the example of how it should look (this is not what I need, but it solves the main task PS In the comments ):




In the process, I found some information a couple of examples:
1 , 2

Answer 1

Can't draw on top of another control in WinForms