Absolute positioning of grafics in ConTeXt

[Johannes Fichtinger <jotfi@yahoo.de>]

Hi all, 

I'm quite new to ConTeXt, but I've been working with LaTeX for several years
now. Now I faced a problem which I'm not able to solve in LaTeX which
probably can be solved in ConTeXt:

I need a possibility to set grafics in a book on exact, absolute positions.
Now I found the way for background images, like in the attached example.
But obviously, normal text is written above the background image. I need
now a possibility like this but for foreground grafics.

So, how can I set the position of grafics absolutely in ConTeXt?

Thanks,
Johannes.

My example:

--------------------------------------------------------------
\enableregime           [il1]
\mainlanguage           [de]
\setuplayout            [grid=yes,marking=on,horoffset=2cm,veroffset=2cm]
\definepapersize        [jo][width=14cm,height=18cm]
\setuppapersize         [jo][a4]

\useexternalfigure[wr][dpm][type=png, width=5cm, height=4cm]
\definelayer[wr-layer]
\defineoverlay[wr-overlay][\composedlayer{wr-layer}]
\setupbackgrounds[page][background={wr-overlay}]

\starttext

\setlayer[wr-layer][x=-0.1cm,y=-0.1cm]{\externalfigure[wr]}
Blablabla

\stoptext
--------------------------------------------------------------