[NTG-context] texteuro

I clearly have some misunderstanding about the typesetting of the euro sign. In an attempt to implement the MathTimes font and expert fontset, I came across a problem with typesetting the euro. I could not redefine the \texteuro. In \showcharacters it stays empty. Doing \definecharacter texteuro to_some_value in a typescript does not work (giving: Runaway argument?) The euro does appear when I define it explicitely (as coming from the marvosym font): \def\euro{\symbol[europe][EUR]} But then \texteuro is still unaffected and therefore doing "\enableregime[mac] € (euro)" does not work. Any pointer how to solve this? yours sincerely, dr. H. van der Meer