I am looking for a way to pass mouse events through a winform without using Form.TransparencyKey.
If there is no simple way to do this, is there a way to send a mouse event to a given window handle using Win32 API?
Edit
By pass through the winform I do not mean to a parent window, I mean to other applications that reside behind mine.
The answer is actually much easier than I thought it would be.
This SO answer got me where I needed to be:
Transparent Window (or Draw to screen) No Mouse Capture
Also found what looks like a c++ implementation if you want some working code:
Transparent Window (or Draw to screen) No Mouse Capture