\ifdefined\directlua\input luaotfload.sty\fi
%% This requires the Cambria fonts from MS.
\directlua{
  inspect(fontloader.info"cambria.ttc")
}
%% Here we load both subfonts in the collection
%% with the not-quite documented subfont syntax.
\font\subfontone="file:cambria.ttc(0)" at 42pt
\font\subfonttwo="file:cambria.ttc(1)" at 42pt
\subfontone foo bar baz \endgraf
\subfonttwo foo bar baz \endgraf
\bye