#32770

DO

h=FindWindow("#32770","Choose file")

DOEvents

Loop Until h

editbox=FindWindowEx(x,0&,"ComboBoxEx32",VbNullString).

SendMessage by string

handle  windows msg:WM_SETTEXT  0& maybe ByVal Text

برای Hook کردن پنجره : 

در Form_Load 

Public Function WindowProc(ByVal hwnd As Long, _ ByVal uMsg As Long, _ ByVal wParam As Long, _ ByVal lParam As Long) As Long Select Case uMsg

Case WM_LBUTTONDOWN

If ............ Then

WindowProc = CallWindowProc(lpPrevWndProc, hwnd, uMsg, wParam, lParam)

End If 

 Case Else 

 WindowProc = CallWindowProc(lpPrevWndProc, hwnd, uMsg, wParam, lParam)

End Select

End Function