How can I read the table of contents's data from a document?

Hello,
I'm writing a C++ code to extract the data from the table of contents:
1. Pages numbers of the start to the end of the table of contents

2. The data inside the table:

  a. Heading: Numbering + text
  b. Page where the Heading exsists
  c. Link to the page where the heading exists.
But I can only find that data inside ITOCCmdData, any help will be appreciated!
Thanks a lot!