MathML.ps1
Add-Type -AssemblyName PresentationCore
$dataObject = [Windows.Clipboard]::GetDataObject()
$memoryStream = $dataObject.GetData("MathML")
if ($memoryStream) {
    $streamReader = [System.IO.StreamReader]($memoryStream)
    $mathML = $streamReader.ReadToEnd()
    [Windows.Clipboard]::SetText($mathML)
}

Запуск
powershell.exe -noprofile -sta -command .\MathML.ps1