LyX ⇒ Hide chapter numbering but show section numbers

[strokine]

It sims like a simple task, but I couldn't find a way to do this.
I have a book which has 2 parts. First part has 12 chapters and many sections, and everything looks fine as is. But second part has just hundreds of sections. I've put a chapter in before the sections of the second part, so the numbers of the sections start from 1, but the chapter has the same name as the second part, so I don't really need to show it.
So now I have 13th chapter with the same name as the second part which has hundreds of sections.
The numbers goes like 13.1, 13.2 etc... But I'd really would like to see 1, 2, 3, etc... and don't want to see the chapter at all.
How could I achieve this?
Thanks in advance.

[strokine]

I've got it work with such TeX code which I inserted right after the second part name:

Code: Select all

\markboth{left}{Second Part Title}
\renewcommand*\thesection{\arabic{section}}

First line replaces left part of page header for second part. If I don't have it, I just see previous chapter's title.
Second line hides 13th chapter's number, and shows only section numbers.
This is still not perfect, because I need to duplicate the second part name in the code. But I guess there is the way just to show the title of the current part somehow else. Yet to be discovered ))
Thank you