How to rewrite cond to a specific subdirectory?

Question

htaccess

There is a code that translates all .html to /
RewriteRule ^(.*)\.html$ /$1 [L,R=301]
How to make it not work for products, namely:
http://domain.com/katalog/{категория}/{товар}.html

Answer 1

Add rule:!^/katalog/(.[a-z0-9]+)/(.[a-z0-9]+)\.html