If the note is only used in one place:
1) Make an anchor at start of paragraph* at place where link to note is.
2) Add the text < Back at the end of the note and link it to paragraph Anchor.
In MS Word you can set an anchor inside a paragraph, or even to a selection. That causes errors in Save As "HTML", or import to ODT in Writer or upload to Amazon or eBook creation tools. An ebook (mobi, AZW, epub) etc is internally very like a webpage, properly an Anchor is only at the start of a paragraph, which is often a styled heading, but any bodytext paragraph can have an anchor (what wordprocessors call bookmarks).
You can use the same techniques in HTML view of any Website CMS editor, in which case links to an anchor on a different page have a relative or full path prefixed with # instead of HTTP:// (or
HTTPS://)