Trouble with button pushes outside of app - vb.net

Question

Using Spy++ I've been trying to control form buttons on an external program with my own program..
The picture shows what control I am attempting to mimic and here's my following code below...
Dim hWnd As IntPtr = FindWindow(vbNullString, ListView4.SelectedItems(0).SubItems(3).Text)
If hWnd.Equals(IntPtr.Zero) Then
Return
End If
Dim hWndButton As IntPtr = _
FindWindowEx(hWnd, IntPtr.Zero, "Button", "Load Settings")
If hWndButton.Equals(IntPtr.Zero) Then
Return
End If
However nothing happens when I run the code.. one possibility is the window name I'm grabbing is wrong, but if that's not the case is my code correct?

Answer 1

Well, as Alex pointed out, I wasn't actually initiating the button press.. now that he pointed that out I was able to fix my code.. Here's what I now use:
Private Declare Auto Function FindWindow Lib "user32.dll" ( _
ByVal lpClassName As String, _
ByVal lpWindowName As String _
) As IntPtr
Private Declare Auto Function FindWindowEx Lib "user32.dll" ( _
ByVal hwndParent As IntPtr, _
ByVal hwndChildAfter As IntPtr, _
ByVal lpszClass As String, _
ByVal lpszWindow As String _
) As IntPtr
Declare Auto Function SendMessage Lib "user32" (ByVal hwnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
Private Const BM_CLICK = &HF5
Dim hwndParent As Long = FindWindow(vbNullString, ListView4.SelectedItems(0).SubItems(3).Text)
Debug.Print("findwindow: " & hwndParent)
Dim hwndButton As Long = FindWindowEx(hwndParent, IntPtr.Zero, "Button", "Save as")
Debug.Print("OK: " & hwndButton)
hwndButton = SendMessage(hwndButton, BM_CLICK, 0, 0)
Debug.Print("Clicked: " & hwndButton)