oh, i see. i use http://www.vectric.com/WebSite/Vectric/cut3d/c3d_index.htm
to generate gcode. as i design my things in 3d (cinema4d) and cut3d generates gcode from 3d formats. if you know an alternative, please tell me.
the thing i´m curious now is how do i position my workpiece so that it is milled correctly? do i just place the head somewhere and then put the workpiece relative to this position regarding the settings in the "tools" "options" menu (origin x, origin y)? < confused again 
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is there any way to get the machine finding its 0-axes and then count "absolut" from there on?