How to exclude from 301 redirect url with certain part?

Question

URL Handling

In htaccess, with this line, all pages with .html at the end are sent with a 301 redirect to their counterpart without .html
RedirectMatch 301 (.*)\.html$ /$1/
I need this rule not to work for links that have the component .../ order/xxx.html. This option doesn't work for me:
RewriteCond %{REQUEST_URI} !^/order
RewriteRule ^(.*)\.html$ /$1/ [R=301,L]
This kind of exception doesn't work either:
RewriteCond %{REQUEST_URI} ! ^/order\.html$
Tell me, please, how to write an exception correctly.

Answer 1

RedirectMatch 301 ^((?:[^/]*/)++(?<!/order/).*)\.html$ $1/

RewriteEngine On

RewriteCond %{REQUEST_URI} !/order/[^/]+$
RewriteRule ^(.*)\.html$ /$1/ [R=301,L]