[NTG-context] sometimes \rightaligned

Hallo, I have an other problem which was asked for years if I remember right. But I can not find it. In the following \starttext \startnarrower Und Gott der Herr machte Adam und seinem Weibe Röcke von Fellen, und kleidete sie. \RA{\tfx (Genesis 3, 21)} \stopnarrower \stoptext I want \RT a macro which does nothing if there is enough space on the right to set the whole argument and puts the argument in a new line, rightaligned otherwise. Can someone remember who has asked this before, or a fresh solution alternativly. thank you Wolfgang