Find a Window by the Win32 Api

The sample finds the window of a parent window by its caption and returns its handle. If you want to find a window of the top level, first call the GetDesktopWindow function and pass the result to the FindChildWindowText function. But you can also pass the handle of any other window to find one of its childs. Lower or upper cases don't matter; and you can search for exact matches or just a part of it by using a trailing asterisk (e.g. 'abc*').

Add a new module via Insert / Module, and paste the code there.

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Private Declare Function GetWindow Lib "user32" _
  (ByVal hwnd As Long, ByVal wCmd As Long) As Long
Private Declare Function GetWindowTextA Lib "user32" _
  (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
Private Declare Function GetDesktopWindowA Lib "user32" _
  Alias "GetDesktopWindow" () As Long

Const GW_HWNDNEXT = 2
Const GW_CHILD = 5

Public Function GetDesktopWindow() As Long
  GetDesktopWindow = GetDesktopWindowA
End Function

Public Function FindChildWindowText(ByVal lHwnd As Long, _
  sFind As String _
) As Long
  Dim lRes As Long
  Dim sFindLC As String

  lRes = GetWindow(lHwnd, GW_CHILD)
  If lRes Then
    sFindLC = LCase$(sFind)
    Select Case InStr(sFindLC, "*")
    Case Is > 0
      Do
        If LCase$(GetWindowText(lRes)) Like sFindLC Then
          FindChildWindowText = lRes
          Exit Function
        End If
        lRes = GetWindow(lRes, GW_HWNDNEXT)
      Loop While lRes <> 0

    Case Else
      Do
        If LCase$(GetWindowText(lRes)) = sFindLC Then
          FindChildWindowText = lRes
          Exit Function
        End If
        lRes = GetWindow(lRes, GW_HWNDNEXT)
      Loop While lRes <> 0
    End Select
  End If
End Function

Private Function GetWindowText(ByVal lHwnd As Long) As String
  Const STR_SIZE As Long = 256
  Dim sBuffer As String * STR_SIZE
  Dim lSize As Long

  sBuffer = String$(STR_SIZE, vbNullChar)
  lSize = GetWindowTextA(lHwnd, sBuffer, STR_SIZE)
  If lSize > 0 Then
    GetWindowText = left$(sBuffer, lSize)
  End If
End Function