Mike,
I do not think this works in Notepad, but it absolutely does in MS-Word (and I just tested it using your example).
You must use Advanced find and replace and you must check the checkbox for "Use Wildcards" after hitting the "More" button in the Find & Replace dialog to make that checkbox visible.
Using the following in the find field: ([0-9]{1,}%)*^13
will find any line starting with one or more numeric digits, followed immediately by a percent sign, followed by any number of characters, followed by a new line/new paragraph.
If you use nothing (leave blank) the replacement it will remove the lines.
--
Brian - Windows 10 Pro, 64-Bit, Version 1903, Build 18362
Many of the insights of the saint stem from his experience as a sinner.
~ Eric Hoffer