Import into a spreadsheet with
\ as the delimiter, sort on the requisite column, then export as text with
\ as the separator.
So goes the theory, (which works here).
You'll probably get a few lines with trailing multiple
\ which can be easily removed by loading into an editor, (eg.
Notepad2-mod), and doing a RegEx Search/Replace:
Search: ^(.*?)(\\+)$
Replace: \1