[NTG-context] abbreviations as macros

Hi Hans: This is asking Armin Varmaz' question in a different way, although I know even less. I would like to define a macro that is just an abbreviation. For example, say I want to define a snippet \NPV which provides the text NPV$_0$, and NPV is in textfont while 0 is in mathfont. This should work everywhere---formulas, subscripts, footnotes, etc., and automatically appear in the correct sizing. In LaTeX, this is easy to do: \newcommand{\NPV}{\text{NPV\ensuremath{_0}}} I can now use \NPV\ in formulas, footnotes, subscripts, titles, etc., and it is properly sized everywhere. Is there a recommended way to do this on conTeXt? regards, /iaw