[dnsdist] Rule for lowering the TTL for a specific qname with qtype TXT

[Tom]

Hi list

I'm struggling with implementing the following dnsdist rule/behavior:
If...
a) qname starts with "_acme-challenge" AND
b) qtype is TXT AND
c) RCODE is NXDOMAIN
then
lower the response TTL to 30s.

What's the best way to achieve this? With a LUA rule or perhaps with 
"addAction(AndRule..."?

Thanks in advance for any hints.
Tom