Manipulate Afx OLE Control in External Window - powershell

Question

I have to manipulate (including get and set text from) an accounting system using Powershell.
The process has a window which contain a grid-like container (the one with blue background colour in the screenshot).
The container contains some Text fields and Combo-boxes.
I tried different ways to get the UI controls(The Text fields/'Edit' Controls in the container).
I tried UIAutomation as follow but fail to found any Text field/'Edit' Control but found the Comobo-box.
Add-Type -AssemblyName UIAutomationClient
$ele=[System.Windows.Automation.AutomationElement]::FromHandle($hwnd)
$elecol=$ele.FindAll([System.Windows.Automation.TreeScope]::Descendants,
[System.Windows.Automation.Condition]::TrueCondition)
for ($i=0;$i -lt $elecol.count;$i++){$elecol[$i].Current} #Only found Scroll Bars & Combo
If look into the "AutomationElement.Current" of container itself ($ele.Current), it looks like the following.
ControlType : System.Windows.Automation.ControlType
LocalizedControlType : pane
Name :
AcceleratorKey :
AccessKey :
HasKeyboardFocus : False
IsKeyboardFocusable : False
IsEnabled : True
BoundingRectangle : 350,1658,2830,443
HelpText :
IsControlElement : True
IsContentElement : True
LabeledBy :
AutomationId :
ItemType :
IsPassword : False
ClassName : AfxGWOleControl42
NativeWindowHandle : 3409268
ProcessId : 11656
IsOffscreen : False
Orientation : None
FrameworkId : Win32
IsRequiredForForm : False
ItemStatus :
And if looks into the supported Patterns ($ele.GetSupportedPatterns()) of the container, it shows nothing.
I also tried using WinAPI to Enum All Child Windows but found No Text field/'Edit' Control too.
function Enum-ChildWindows{
[CmdletBinding()]
param (
[Parameter(ValueFromPipeline = $true)]
[intPtr]$Hwnd
)
BEGIN{
if (("EnumChildWindowsAPI" -as [type]) -eq $null){
Add-Type #"
using System; // namespace "IntPtr"
using System.Runtime.InteropServices; // namespace "DLLImport"
using System.Collections.Generic; // namespace "List"
public class EnumChildWindowsAPI
{
[DllImport("user32")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool EnumChildWindows(IntPtr window, EnumWindowProc callback, IntPtr i);
public static List<IntPtr> GetChildWindows(IntPtr parent)
{
List<IntPtr> result = new List<IntPtr>();
GCHandle listHandle = GCHandle.Alloc(result);
try
{
EnumWindowProc childProc = new EnumWindowProc(EnumWindow);
EnumChildWindows(parent, childProc,GCHandle.ToIntPtr(listHandle));
}
finally
{
if (listHandle.IsAllocated)
listHandle.Free();
}
return result;
}
private static bool EnumWindow(IntPtr handle, IntPtr pointer)
{
GCHandle gch = GCHandle.FromIntPtr(pointer);
List<IntPtr> list = gch.Target as List<IntPtr>;
if (list == null)
{
throw new InvalidCastException("GCHandle Target could not be cast as List<IntPtr>");
}
list.Add(handle);
return true;
}
public delegate bool EnumWindowProc(IntPtr hWnd, IntPtr parameter);
}
"#
}
}
PROCESS{
return [EnumChildWindowsAPI]::GetChildWindows($Hwnd)
}
}
And of course, sending WM_SETTEXT message to the container is also not working.
Watching into the Spy++, the class name of the grid-like container is "afxGWOleControl", shown as follow.
An interesting thing is, the combo box "window" appear in Spy++ only when it is on selected.
Is there any way to edit/read the text field inside the container?