程序代码：

Option Explicit

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

Private Sub Form_Load()
Const SCICALL As String = "SciCalc"
    Dim lret As Long
    lret = FindWindow(SCICALL, vbNullString)
    Do While lret
        Debug.Print "SciCalc", Hex$(lret)
        lret = FindWindowEx(0, lret, SCICALL, vbNullString)
    Loop
End Sub