[NTG-context] Float placement in margin

Dear all, I would like to put a figure my edge margin, at the bottom of the page. (so, the bottom left corner on my left pages). I tried \inmargin but the figure is not placed in margin but at the top of the page. I tried \placefigure[margin] but it is placed on the top of the margin. This is nearly what I want :) Any clue for me ? Thanks in advance, Antoine