I am fairly sure the Lucida font has oldstyle numbers. But I don't get them with the \os macro. Here two minimal examples. The one with lmodern does the oldstyle numbers, the one with lucida not. I would be obliged for a solution.

Hans van der Meer

\setuppapersize[A6][A6]
\setupbodyfont[lucida] % the other example has [lmodern]
\starttext
\type{\setupbodyfont[lucida]}\crlf
numbers {\rm 1234567890} in rm\crlf
numbers {\os 1234567890} in os\par
\stoptext