How to import a custom action group from a file

[ohrenkino]

It looks to me as though you simply add the contents of COMMENT to GENRE
For that procedure, there is even a post in the FAQs:

Actions and batch-operations

How to append the string " xyz" to the content of a tag field? Create a new action in an existing action group and choose Format value as action type. Field specifies the tag field the formatting rule should be applied to. Format string must have the field placeholder for the field selected above and the string which should be appended. Example: If you want to append the string " xyz" to the current value of the comment field: Action type: Format value Field: COMMENT Format string: %com…

In your case, I would create an action group with 3 actions:

1. Format tag field for GENRE
   Format string: %genre%\\%comment%
2. Merge duplicat tag fields for GENRE
   Separator: ;
3. Replace for GENRE
   Search: &
   Replace with: ;

That should lead to the same result as your list. No ELSE required.