'以下在Form
Private Sub Command1_Click()
Call EnableHook
MsgBoxTitle = "MyTitle5"
MsgBox "haha", vbYesNo, MsgBoxTitle
Call FreeHook

End Sub

'以下程式在.Bas
 Declare Function SetWindowsHookEx Lib "user32" Alias "SetWindowsHookExA" (ByVal idHook As Long, ByVal lpfn As Long, ByVal hmod As Long, ByVal dwThreadId As Long) As Long
 Declare Function UnhookWindowsHookEx Lib "user32" (ByVal hHook As Long) As Long
 Declare Function CallNextHookEx Lib "user32" (ByVal hHook As Long, ByVal nCode As Long, ByVal wParam As Long, lparam As Any) As Long
 Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
 Declare Function SetWindowText Lib "user32" Alias "SetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String) As Long
 Declare Function EnumChildWindows Lib "user32" (ByVal hWndParent As Long, ByVal lpEnumFunc As Long, ByVal lparam As Long) As Long
 Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal hwnd As Long, ByVal lpClassName As String, ByVal nMaxCount As Long) As Long

 Public Const HCBT_ACTIVATE = 5
 Public Const WH_CBT = 5

 Public hHook As Long
 Public MsgBoxTitle as String

 Public Sub EnableHook()
 If hHook = 0 Then
    hHook = SetWindowsHookEx(WH_CBT, AddressOf HookProc, 0, App.ThreadID)
 End If
 End Sub
 Public Sub FreeHook()
 If hHook <> 0 Then
    Call UnhookWindowsHookEx(hHook)
    hHook = 0
 End If
 End Sub

 Public Function HookProc(ByVal nCode As Long, ByVal wParam As Long, ByVal lparam As Long) As Long
 If nCode < 0 Then
    HookProc = CallNextHookEx(hHook, nCode, wParam, lparam)
    Exit Function
 End If
 '当MsgBox Activate之前去更改Button的标题
 If nCode = HCBT_ACTIVATE Then
    Dim str5 As String
    Dim len5 As Long, i As Long
    str5 = String(255, 0)
    len5 = 256
    i = GetWindowText(wParam, str5, len5)
    str5 = Left(str5, InStr(1, str5, Chr(0)) - 1)
    '如果Active Window上的标题是MsgBox上的标题
    '
    If str5 = MsgBoxTitle Then
       '取得MsgBox上的所有子window
       Call EnumChildWindows(wParam, AddressOf ChgButtonTitle, 0)
    End If
 End If
 HookProc = 0 '令待完成的动作继续完成，若为1，则取消原本要完成的动作
 End Function

 Private Function ChgButtonTitle(ByVal hwnd As Long, ByVal lparam As Long) As Long
 Dim clsName As String, len5 As Long, i As Long
 Dim Title As String
 If hwnd = 0 Then
    ChgButtonTitle = 0
    Exit Function
 End If
 clsName = String(255, 0)
 len5 = 256
 i = GetClassName(hwnd, clsName, 256)
 clsName = Left(clsName, InStr(1, clsName, Chr(0)) - 1)
 Title = String(255, 0)
 i = GetWindowText(hwnd, Title, 256)
 Title = Left(Title, InStr(1, Title, Chr(0)) - 1)
 '找到Button型态的子Window，并更改其上的标题
 If clsName = "Button" Then
    If Title = "是(&Y)" Then
       Call SetWindowText(hwnd, "Yes(&Y)")
    Else
       If Title = "否(&N)" Then
	  Call SetWindowText(hwnd, "No(&N)")
       End If
    End If
 End If
 ChgButtonTitle = 1 '表示继续找下一个子Window
 End Function