This is what I generally do. It's a rare document where I actually have to create it in some specific version of anything. I then just take the .rtf and open it in whatever other program is needed, or literally just cut and paste it in with formatting, possibly conforming it to some template in the process.I just use *.TXT (plain text) "by default", and if I need to make a text with different fonts, bold, italics, etc., then I just use *RTF (rich text). It can be done with just Notepad or WordPad (Windows) or TextEdit (Mac). I've always disliked using Word.
And for those more specific things, I quite often use some ancient version of whatever program is current. The backward compatibility almost always bails me out without much fuss.