Could you post your RegEX expression, please (as zip or rar)?
There is a tool in OO to create a TOC, btw. You could use that and link the chapters to that TOC.
If you use Calibre, you can use Calibre to create a TOC with XPath (works largely like RegEx) You use a tag, class, or even recurring word to create those. Instructions can be found in the Calibre manual (online at Kovid's site)