The easiest way to do this is with bookmarks.
Highlight the word or section you wish to go to - on the insert ribbon select bookmark. Give it a name that makes sense e.g. bmk_section1
Then go to the word that you wish to make a link to this section in the Appendix
Highlight it and click ctrl + K or insert hyperlink from the menu. Choose the option on the left that says place in this document and select the bookmark name.
Done