[NTG-context] Getting file name of \externalfigure in the header/footer (mkii)

Hi folks, I have a file that I use to combine PDF files in one bigger file. The pages are A4 or A3, rotated or not. This results in a mixed A4/A3 document that I can print and distribute. Example page: \page\setuppapersize[A4,portrait][A4,portrait] \setuplayout[backspace=10mm,topspace=10mm,width=277mm,height=190mm,header=5mm,footer=1mm] \rotate[rotation=90]{\externalfigure[Exercise-1a-B2B-web-site-Anna-A.pdf][width=\hsize]} I'd like to have the name of the external file in the header. Can I do that? G PS. I'm still using mkii for my production (only used mkiv for a transformation to EPUB 1.5 ears ago).