There was (still is?) a Microsoft document that is written and displayed exactly like an HTML web page. From it you
can write a dos command in the HTML code to execute. You don't have to do anything special. By clicking on a button I launched msconfig (and other things). The document is stand alone on my computer so there are no security issues. There is no server
involved (just the document on my computer).
I can't remember the extension of the document (obviously not htm or html; The document's extension might have started with the letter m). I don't think the type of document was/is well known.
P.S. I am a newbie to the Microsoft forums, so had to guess on which forum to post. Also, I'm not making this up. There
was indeed such a HTML web like document because I used it. I lost the information when transferring data from old to new computers.