VB怎样获得桌面指定程序的窗口句柄

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long
'这是定义获得窗口句柄的API函数.
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long,lParam As Any) As Long '这句是定义向获得窗口句柄发送按键消息的API函数.

例子:你先建一个工程
form1.caption="12345
画一个command1 名字为 "确定1"
事件
Private Sub Command1_Click()
msgbox Me.Hwnd '显示确定按钮的句柄
End Sub
生成12345.exe
关闭VB6
打开VB6
再建一个工程 代码如下：

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As St