@Perkin,
What you have asked for is to create a piece of simple HTML as a .txt file and use Word as a text editor to change it and re-save as a txt file.
In these circumstances I would not just be typing the word
Dummy I would also be typing the surrounding <p>...</p> paragraph tags. Here are the contents of dummy_out.txt
Code:
<html><head><title>Dummy</title></head>
<body>
<p>Dummy</p>
</body>
</html>
I have also attached a picture of what I see in Word during the edit.
If I rename dummy_out.txt to dummy_out.htm it opens in my browser.
I'm not really sure what prompted your request but there are very few circumstances when I would use Word as my 1st-choice text editor for editing HTML files. I find Notepad++ easier to use. I do however use Word heavily to generate the initial HTML from a .doc WYSIWYG file, in the first place.
In these circumstances I would:
Open a brand new blank Word .doc file
Type the word Dummy
Apply the built-in style Normal(Web)
Save-as webpage_filtered to Dummy2.htm
The resulting piece of HTML (Dummy2.htm) would have quite a lot more in it (I've attached a screenshot of what it looks like in Notepad++) but would look the same as dummy_out.htm when opened in a browser.