[NTG-context] Position Box On Bottom Right Side

Hello! i want to put a box on the right, bottom side of my initial page. Its like \blank[10*big,force] but without the 10! Lets say i got three lines, then the third line should be the last line on this page. I thought aboud a \vbox with frame=off, which contents are \startalignment[left] and in a \startlines environment. As special i want to put a \hairline in that, with \textwidth length. Other things went very quickly, but this one seems very tricky... :-( ... for me. :-) Thanks for Help! Christoph