export part of an index as metric

[Andy1616]

hi out there

I need to export part of an index as a metric.

What? Why?
In detail:
Juniper: jnxPingLastTestResultTable contains an index "jnxPingCtlTestName" which is perfectly added to all the metrics as a tag.

In our case that jnxPingCtlTestName string contains a number that I can extract by regex and need to see exposed like an additional metric.

Assumption:
walk:
- jnxPingLastTestResultTable
overrides:
jnxPingCtlTestName:
regex_extracts:
'Threshold':
- regex: '_(\d+)ms'
value: '$1'
type: gauge

did not do the expected, hence did not add a metric for jnxPingCtlTestNameThreshold

Did I do wrong? How to do correct???

Any hint is welcome - thanks a lot.