Talvez você possa usar a API do Win32 via PowerShell para encontrar e ocultar a (s) janela (s) do aplicativo de destino.
Exemplo de código:
$definition = @"
[DllImport("user32.dll")]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
public static void Show(string wClass, string wName)
{
IntPtr hwnd = FindWindow(wClass, wName);
if ((int)hwnd > 0)
ShowWindow(hwnd, 1);
}
public static void Hide(string wClass, string wName)
{
IntPtr hwnd = FindWindow(wClass, wName);
if ((int)hwnd > 0)
ShowWindow(hwnd, 0);
}
"@
add-type -MemberDefinition $definition -Namespace my -Name WinApi
[my.WinApi]::Hide('Notepad', 'Untitled - Notepad')
Código-fonte de A resposta de Aryadev para "Ocultar uma janela com PowerShell ISE?" no StackOverflow.