A solution which uses only existing commands in the document.
\startsetups [martin] \startlua local points = tonumber(\getvariable{martin}{question}) or 0 ; points = points * 92 ; local answer = 42 ; context.setvariable("martin","points",points) ; context.setvariable("martin","answer",answer) ; \stoplua \stopsetups
\setvariable{martin}{set}{\directsetup{martin}}
\starttext
\setvariables [martin] [question=44]
Points: \getvariable{martin}{points}
The answer is \getvariable{martin}{answer}.
\stoptext
Hello Wolfgang, what exactly does the command "\setvariable{martin}{set}{\directsetup{martin}}"? I don't understand it. Has it something to do with "Command/datasetvariable"? Especially what does "\directsetup"? Rudolf