Put it on mute and just watch the menu he is using
this solution though is not "general" - I use Writer and I did that long time ago. Whenever you copy paste the text elsewhere, all the numbers would change to "Arabic numerals" (123...etc). So, this thing or solution is only workable inside the environment of the text editor alone.
Yeah the rest is on the forum post. I know how to set it in Writer (I didn't use Word in ages). Nevertheless, in both programs it's just a matter of display (and maybe printing later on). As you saw, copying and pasting the thing into the web would mostly change to Arabic numerals. Not only that; When I work in Photoshop (mine is non-ME version) and I try to make something with Hindi numerals, I would copy the numerals from the character map program into Photoshop, but Photoshop also turns them into Arabic numerals instead.