% example posted by Wolfgang on the list:

\ctxcommand{doif(jit)}{\endinput} % sorry luigi ...

\starttext

\startusercode

entries = {
    one   = "1",
    two   = "2",
    three = "Three",
    five  = "More text!"
}

function getentry(name)
    local entry = entries[name] or ""
    global.context(entry)
end

\stopusercode

\define[1]\getentry{\usercode{getentry("#1")}}

\starttabulate
\NC one   \EQ \getentry{one}   \NC\NR
\NC two   \EQ \getentry{two}   \NC\NR
\NC three \EQ \getentry{three} \NC\NR
\NC four  \EQ \getentry{four}  \NC\NR
\NC five  \EQ \getentry{five}  \NC\NR
\stoptabulate

\stoptext
