[NTG-context] Typesetting levels of index differently

[Sytse Knypstra]

Dear list members,

I would like the second level of an index item be typeset differently 
from the first level, e.g. as in

\starttext
\index{level+{\it second}}
\completeindex
\stoptext

Instead of adding {\it ... } to each \index separately, could this be 
realized systematically, in e.g. one \setupregister command:

\setupregister[.?.]
\starttext
\index{level+second}
\completeindex % rendering 'second' as italic
\stoptext

Sytse