Add entry to existing TOC

I have a TOC with Chapter headings and Head3 entries. Below head 3 level in the main document I have a para of a certain style I want to add to the content so i can easily see certain progress points as I write the novel. I have tried to use the Edit index but can’t see where I can choose this para style to go into the TOC. I assumed it would be under the Entries tab but I cn’t see how this is done. Help appreciated. Thanks.

On the Type tab of the dialog box for inserting/editing a TOC is an option Additional styles. Tick that and then add click Assign styles... to add your special style.

Alternatively to @anon87010807’s answer, you can customise your paragraph style to make it part of the outline.

  • Go to the Outline & List tab of said paragraph style
  • Choose an Outline level from the drop down menu to assign a level to this style
  • OK

Refresh the TOC.

Always nice to receive feedback, but this is no solution to your problem. It should have been posted as a comment. So, please, do and delete your non-answer.
It seems to me that you second sentence is another question. In a Question & Answer site (this is not a forum), the rule is one post = one question to facilitate problem search by user. Be kind enough to ask a new question, giving more details. Which style alters what? Headings and TOC are formatted by different styles, unless you changed that.