This is dictation.
That looks very clever. I never thought about using VBScript to start up the speech recognition engine that is built into Microsoft Windows.
If you're using Windows 10, there already are applications that make it easy to convert speech to text. Here is one of many such references.
http://www.pcworld.com/article/2834835/stop-typing-and-start-dictating-documents-in-windows.html.
Sorry, I'm not able to help you with the script. For one thing, it's much more difficult for me to write scripts that used to be now that I am getting old. Moreover, I don't feel motivated to write a batch file to start up the speech to text converter. It's easier for me just click my mouse on a suitable application and start dictating.
Besides Windows 10, speech to text conversion has been around for a while and there are some programs available at very low costs that do it for you. But if you're using Windows 10, you don't have to buy anything extra. There are apps in the Windows store for free that will make it easier.
But don't let me discourage you. In your post you should also include some information about which version of Windows you're using and also do you have all the libraries installed on your computer. I mean the libraries that are needed for the Microsoft .NET stuff.
Here's a question. Would it not be possible to write a program in Visual Studio rather than using VBScript?
Hopefully one of the other members can help you with your script.