C#

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr GetWindow(IntPtr hWnd, uint uCmd);

[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);

 int x = 283; // X coordinate of the click
 int y = 342; // Y coordinate of the click

 IntPtr handle = two.Handle;
 StringBuilder className = new StringBuilder(100);

 while (className.ToString() != "Internet Explorer_Server")//The class control for the browser
 {
     handle = GetWindow(handle, 5); // Get a handle to the child window
     GetClassName(handle, className, className.Capacity);
 }

 IntPtr lParam = (IntPtr)((y << 16) | x); // The coordinates

 IntPtr wParam = IntPtr.Zero; // Additional parameters for the click (e.g. Ctrl)
 const uint downCode = 0x201; // Left click down code
 const uint upCode = 0x202; // Left click up code
 SendMessage(handle, downCode, wParam, lParam); // Mouse button down
 SendMessage(handle, upCode, wParam, lParam); // Mouse button up