Adding to Your List of Actions

Not sure exactly what you mean by this, but ALL KM Actions are directly available to insert into your Macro by any of these means:

  1. Display the Actions Panel (⌘K)
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  2. Use the menu Edit > Insert Action
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  3. Use the prompt/search Insert Action by Name (⌘⌃A)
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Did you try a forum search for batch rename file ?

At the top of the list:

Most authors (including myself) do NOT provide a trigger so that the user who downloads the Macro can import it safely and then assign their own trigger.
Even if a trigger is included, it is easy to delete it and assign your own trigger. Do you need help with this?