Private Const HWND_TOPMOST = -1
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Private Declare Function GetWindowRect Lib "user32" (ByVal hwnd As Long, lpRect As RECT) As Long
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function SetWindowPos Lib "user32" (ByVal hwnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long

Private Sub Form_Load()
Timer1.Interval = 50
End Sub

Private Sub Timer1_Timer()
Dim h As Long, r As RECT
h = FindWindow("notepad", vbNullString)
GetWindowRect h, r
SetWindowPos hwnd, HWND_TOPMOST, r.Left, r.Top, r.Right - r.Left, r.Bottom - r.Top, 0'这句关键
End Sub