C# usercontrol cursor position

        [DllImport("user32.dll")]

        public static extern bool GetCaretPos(out System.Drawing.Point ppt);

        private void TextBoxParameter_Click(object sender, EventArgs e)

        {

                 // TextCursorPosition  

                System.Drawing.Point p;

                GetCaretPos(out p);
                lastCursorPosition = this.GetCharIndexFromPosition(p); 

         }