[XeTeX] aligning section- and subsection etc. titles

[Jens Bakker]

Dear Ladies and Gentlemen,

I would like to ask if there is a possibility to achieve the alignment of the titles of the sections, subjections, and so forth, after the numbers, so that the following picture is achieved if they appear one immediately before the other:

1		Introduction
1.1		Preliminaries
1.1.1	The Project


I did not find any solution to that problem, and it seems, that it is not possible to put the sectionnumbers into the \makebox[1cm]{} order, as for example is possible with \fbox as is explained in Mittelbach - Goossens: Latex-Begleiter (2.2.1, p.29).

The following: 

\makeatletter
\renewcommand\@seccntformat[1]{\makebox[5ex]{\csname the#1\endcsname}\hspace{0.5ex}}
\makeatother

does not work.

With many thanks and best regards,
Jens Bakker