If you follow Paul's method, you could even set up your heading styles so that the tabbed material you want in your TOC would be tabbed past the edge of the page. (This is if you do not want this to show up in the body of your document but only in the TOC.)

Another alternative would be a TC field, perhaps with a StyleRef field to your headings.
See:

• TOC Tips and Tricks by Suzanne Barnhill, MVP
• Useful StyleRef tricks by Suzanne Barnhill, MVP