We have a database where there’s a single field, args, into which the vendor has glommed quite a few different things. Unfortunately, I need one of those numbers.

"---
- Workbook
- 4477
- Sample Report
- 18116
- null
"

You can use split_part to break a column into elements and only use one of those elements split_part(column_to_split, delimiter, ColumnToKeep)

As an example:
SPLIT_PART(b.args, E'\n', 3)AS task_workbook_id

In this case, I subsequently needed to eliminate the dash and space that prefixed the line. Using TRANSLATE, I am removing the ‘- ‘ with ”:
TRANSLATE ( SPLIT_PART(b.args, E'\n', 3), '- ','') AS task_workbook_id

And now I’ve just got 4477