C# WinAPI - FindWindowEx

using System.Runtime.InteropServices;

[DllImport("user32.dll")]
private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

[DllImport("user32.dll")]
private static extern IntPtr FindWindowEx(IntPtr hWnd1, IntPtr hWnd2, string lpsz1, string lpsz2);

private IntPtr FindHandleEx(String winName)
{
	IntPtr handle1 = FindWindow(null, winName);
	IntPtr handle2 = FindWindowEx(handle1, IntPtr.Zero, null, "자식창이름");
	return handle2;
}