How to I enable "clickthrough" in windigo?

[offles2]

If I have a Window, I need to be able to "clickthrough" it, such that mouse actions affects the background Window like as if this Window does not exist.

In WPF I achieve this via :

       protected override System.Windows.Forms.CreateParams CreateParams
        {
            get
            {
                CreateParams cp = base.CreateParams;
                cp.ExStyle = cp.ExStyle | WS_EX_TRANSPARENT;
                return cp;
            }
        }