Thank you all for your input at suggestions. Before I posted my question I did a search in the Wiki and the mailinglist archive but didn't find a clue. Finaly I got a working minimal example. The with \definedfont[file:...] I found out that I can use every Font that ist installed on my Windows System. Is this a correct way for font switching for a special markup or is there a better or more correct way? kind regards Wolfgang Murth %==================================== %------------------------------------ % % Define language \language[de] \mainlanguage[de] %------------------------------------ % % Bodyfont Helvetica \usetypescript[helvetica][texnansi] \setupbodyfont[helvetica,ss,10pt] %------------------------------------ % % Excel Funcions and Formulas \def\xlf#1{{\definedfont[file:texgyreheroscn-bold*regular at 10pt]#1}} \starttext \chapter{Excel Time and Date} When using Time and Date calculations with Excel important functions are \xlf{DATUM} and \xlf{ZEIT}. \stoptext %====================================