Transform regex replace

Oh sure, sorry. I forgot this information.

The string is coming from DWD warnings, as you can see here:
https://community.openhab.org/t/solved-json-path-weather-warnings-dwd-deutscher-wetterdienst/46295

At the rule I post the warnings description to my item:

DWD_Warnung_description.postUpdate(transform("JSONPATH","$.description",newString))

I addition to this, I want to send the warning to Alexa.

AmazonEchoDotWohnzimmer_Speak.sendCommand("Warnung des Deutschen Wetterdienstes" + DWD_Warnung_headline.state.toString + DWD_Warnung_description.state.toString + DWD_Warnung_instruction.state.toString)

Alexa doesnt know km/h so it sounds really weired. I’m looking now for a solution, how to replace eg. km/h with “Kilometer pro Stunde” and removing all content of the ( … ) within this rule.

Best regards
Tobias