Create cmd line for youtube-dl to download audio from a specific section of a video in mp4 form
 To download audio from a specific section of a video in mp4 format using youtube-dl, you can use the following command line:
```css
youtube-dl -ss [start_time] -t [duration] -x --audio-format mp3 [video_URL]
```
Here's what each option does:

* `-ss [start_time]`: This option specifies the start time of the section you want to download. Replace `[start_time]` with the time in seconds or in the format `HH:MM:SS`.
* `-t [duration]`: This option specifies the duration of the section you want to download. Replace `[duration]` with the length of the section in seconds or in the format `HH:MM:SS`.
* `-x`: This option tells youtube-dl to extract the audio track from the video and save it as a separate file.
* `--audio-format mp3`: This option specifies the format you want to save the audio file in. In this case, we're using mp3, but you can also use other formats such as m4a or ogg.
* `[video_URL]`: Replace this with the URL of the video you want to download.

Note that the start time and duration options can be combined into a
youtube-dl -f mp4 -e audio -x '[START_TIME]:[END_TIME]' https://www.youtube.com/watch?v=VIDEO_ID