My Apologies there is a typo in the first replace text (That's happening a lot at the moment as I have a new keyboard)

\1^p\1

should read
\1^p\2

which I did get right further down the page. My old eyes missed the space between the ] and [

The revised search would be

([\]])(*)([\[])

Personally I find the search text quite hard to scan, particularly on my hi res monitor where the search and replace dialog box is tiny.

So on reflection an easier to read version would have been

([^091])(*)([^093])

where 091 and 093 are the decimal ascii codes for [ and ].

You can get more information on find and replace using wildcards by clicking the ? on the find and replace dialog box and first looking under

Search by using wildcards

and then

Find and replace text by using regular expressions (Advanced)