Repear.index in the middle of an attribute's name

Hey fellow “homeassistant” I am since a while ago, a bit confused.
I thought I have enough experience to do whatever I want with Home Assistant but I gave up and I’m asking YOUR help!

That’s where I couldn’t reach the result I wish:

My script:
Read a sensor who contains attributes such:
warning_count: (int)
warning_(an int from 1 to warning_count)_type: (int)

warning_count: 2
warning_1_type: 21
warning_2_type: 81

Now I thought I will use the repeat service, steps: warning count and do the following:

  count: >-
    {{ state_attr('sensor.wetter_warnung_current_warning_level','warning_count')
    - choose:
        - conditions:
            - condition: template
              value_template: >-
                '{ {((state_attr("sensor.wetter_warnung_current_warning_level","warning_"+repeat.index+"_type")
                > 21)) }}'
            - service: input_text.set_value
                value: '{{states("input_text.wetter_warnung")}}, Snow'
              entity_id: input_text.wetter_warnung

I only included one condition to short-down the code, but you got the point.
So, if I have a warning_count: 2 and I replace the +repeat.index+ with 1 I got as expected two times “Snow” in the input_text.wetter_warnung.
So how can I use the repeat.index variable in the middle of warning__type attribute?

Thank you very much for your precious time!

{ {((state_attr("sensor.wetter_warnung_current_warning_level","warning_"+repeat.index|string+"_type" > 21)) }}

Of course I should have converted it to string!