Generate list of columns to exclude when using dbt_utils.unpivot

I am using dbt to create models inside a Snowflake Database. One of my models has many columns, and I want to unpivot some of them using dbt_utils.unpivot. Instead of hardcoding the list of columns I want to exclude from the unpivot, I would like to create the list using a macro that filters all the columns using a regex pattern.

My model looks like this:

WITH unpivot as (

{{ 
  dbt_utils.unpivot(
  relation=ref('my_other_modell'),
  exclude= get_column_names('my_other_modell',regex='^F.*'),
  field_name='vairable_name',
  value_name='vairable_value'
) }})



SELECT * FROM unpivot

and my macro looks like this:

{% macro get_column_names(model_name, regex='+*') %}
    {%- set columns = adapter.get_columns_in_relation(ref(model_name)) -%}
    {%- set column_names = [] -%}
    {%- set re = modules.re %}
    
    {%- for column in columns %}
          {%- if not re.match(regex, column.name) %}
            {%- set _ = column_names.append(column.name) %}
        {%- endif %}
    {%- endfor %}
    
    {{ column_names}}
{% endmacro %}

I have already tried several variations of the macro, like replacing {{ column_names }} with {{ column_names|join(',') }}, but I always get a syntax error like:

syntax error line 16 at position 0 unexpected ','.
syntax error line 17 at position 17 unexpected ','.
syntax error line 18 at position 17 unexpected ','.
syntax error line 19 at position 17 unexpected ','.
syntax error line 20 at position 17 unexpected ','.

Any advice is appreciated

Integrating my macro directly into the dtb_utils.unpivot macro solved my problem. Judging from the logs, it seems that when parsing the output of my macro to the exclude parameter, it gets decomposed into every single character (possibly by some sort of select statement).