Управление чужим приложением через SendMessage

Option Explicit
 
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExW" (ByVal hWndParent As Long, ByVal hWndChildAfter As Long, ByVal lpClassName As Long, ByVal lpWindowName As Long) As Long
Private Declare Function GetWindow Lib "user32" (ByVal hwnd As Long, ByVal wCmd As Long) As Long
 
Private Const GW_CHILD      As Long = 5
Private Const GW_HWNDNEXT   As Long = 2
 
 
Private Sub Form_Load()
    Dim TMain   As Long
    Dim TPanel  As Long
    Dim TGroup  As Long
    Dim btn(4)  As Long
    
    TMain = FindWindowEx(0, 0, StrPtr("TMain"), StrPtr("USB датчик температуры - Мастер Кит - BM1707"))
    If TMain = 0 Then Exit Sub
    
    TPanel = FindWindowEx(TMain, 0, StrPtr("TPanel"), 0)
    If TPanel = 0 Then Exit Sub
    
    TGroup = FindWindowEx(TPanel, 0, StrPtr("TGroupBox"), StrPtr(" Управление каналами "))
    If TGroup = 0 Then Exit Sub
    
    ' // Записать
    btn(0) = GetWindow(TGroup, GW_CHILD)
    ' // Нижняя "Сбросить в 0"
    btn(1) = GetWindow(btn(0), GW_HWNDNEXT)
    ' // Верхняя "Сбросить в 0"
    btn(2) = GetWindow(btn(1), GW_HWNDNEXT)
    ' // Нижняя "Установить в 1"
    btn(3) = GetWindow(btn(2), GW_HWNDNEXT)
    ' // Верхняя "Установить в 1"
    btn(4) = GetWindow(btn(3), GW_HWNDNEXT)
    
    Debug.Print Hex(btn(0))
    Debug.Print Hex(btn(1))
    Debug.Print Hex(btn(2))
    Debug.Print Hex(btn(3))
    Debug.Print Hex(btn(4))
    
End Sub

Option Explicit
 
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Any) As Long
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExW" (ByVal hWndParent As Long, ByVal hWndChildAfter As Long, ByVal lpClassName As Long, ByVal lpWindowName As Long) As Long
Private Declare Function GetWindow Lib "user32" (ByVal hwnd As Long, ByVal wCmd As Long) As Long
Private Type botom
  btn1_1 As Long
  btn1_0 As Long
  btn2_1 As Long
  btn2_0 As Long
End Type
 
Const BM_CLICK = &HF5
Private Const GW_CHILD      As Long = 5
Private Const GW_HWNDNEXT   As Long = 2
 
 
Private Function GetHndl() As botom
    Dim TMain   As Long
    Dim TPanel  As Long
    Dim TGroup  As Long
    Dim btn(4)  As Long
    
    TMain = FindWindowEx(0, 0, StrPtr("TMain"), StrPtr("USB äàò÷èê òåìïåðàòóðû - Ìàñòåð Êèò - BM1707"))
    If TMain = 0 Then Exit Function
    
    TPanel = FindWindowEx(TMain, 0, StrPtr("TPanel"), 0)
    If TPanel = 0 Then Exit Function
    
    TGroup = FindWindowEx(TPanel, 0, StrPtr("TGroupBox"), StrPtr(" Óïðàâëåíèå êàíàëàìè "))
    If TGroup = 0 Then Exit Function
    
 
    btn(0) = GetWindow(TGroup, GW_CHILD)
 
    btn(1) = GetWindow(btn(0), GW_HWNDNEXT)
 
    btn(2) = GetWindow(btn(1), GW_HWNDNEXT)
 
    btn(3) = GetWindow(btn(2), GW_HWNDNEXT)
 
    btn(4) = GetWindow(btn(3), GW_HWNDNEXT)
 
    GetHndl.btn2_1 = btn(1)  
    GetHndl.btn1_1 = btn(2)  
    GetHndl.btn2_0 = btn(3)  
    GetHndl.btn1_0 = btn(4)  
    
    
End Function
 
 
Public Sub Rele1_On()
SendMessage GetHndl().btn1_0, BM_CLICK, 0, ""
End Sub
 
Public Sub Rele1_Off()
SendMessage GetHndl().btn1_1, BM_CLICK, 0, ""
End Sub
 
Public Sub Rele2_On()
SendMessage GetHndl().btn2_0, BM_CLICK, 0, ""
End Sub
 
Public Sub Rele2_Off()
SendMessage GetHndl().btn2_1, BM_CLICK, 0, ""
End Sub