How to automatically import an audio at the end of the current track with a macro?

I manage to automatically import a mp3 file with a macro
However, it inserts it in a new track, I would rather insert it at the end of my current track

How could I achieve this?

Would it be OK for it to be “joined” to the end of the first track, or does it need to remain as a separate audio clip?

If the former, then “Select All” and apply the “Align End To End” command, then “Mix and Render”.

The latter is more tricky because you have to ensure that the imported file has the same number of channels as the initial track.