TS0203 (ZD08) to send Additional value to MQTT

[FreakErn]

Hello Guys, i have a Tuya TS0203 (ZD08). I soldered two switches to this device, which now shows me if my Windows have different Positions.

I do not use HomeAssistant.

Currently my Values are these:

zigbee2mqtt/WindowSensor {"battery":93,"battery_low":false,"contact":true,"last_seen":1736323210083,"linkquality":112,"tamper":false,"voltage":2600}

The Device sends the Values "tamper" and "contact". Both are boolean Values.
tamper = true means for me now "Window Angled"
contact = true means "Window Open"
if both are false means "Window closed"

Can i add a new variable to the MQTT json like this:

state = e.contact == true ? "Window open" : e.tamper == true ? "Window Angled" : "Window closed"

to have this additionally in my MQTT json Message:

..."state":"Window open"...

I copied the external definition from my z2m, but i have absolutely no idea where i could possibly put these values into.

const {battery, iasZoneAlarm, commandsOnOff, commandsLevelCtrl} = require('zigbee-herdsman-converters/lib/modernExtend');

const definition = {
    zigbeeModel: ['TS0203'],
    model: 'TS0203',
    vendor: '_TZ3000_7d8yme6f',
    description: 'Automatically generated definition',
    extend: [battery(), iasZoneAlarm({"zoneType":"generic","zoneAttributes":["alarm_1","alarm_2","tamper","battery_low"]}), commandsOnOff(), commandsLevelCtrl()],
    meta: {},
};

module.exports = definition;

Is this even possible and can someone point me to where i have an example for that?

Thank you in Advance
Dave