Pattern Replace

I need a small help Pattern Replace
forum.pspad.com

example\\.com/(diary/example/){0,1}20[01][0-9]([/-]\\d{2}){2}([/-]\\d+){0,1}
Replace with:
example\\.com/(diary/example/){0,1}20[01][0-9]([/-]\\d{2}){2}([/-]\\d+){0,1}#.html

I want to add extension to the link at the end, this type:
#.html

Edited 2 time(s). Last edit at 2021-04-26 10:06 by Haunebu.

Put whole regular expression into ()
Replace with $1#.html

Very good. Thanks!