Reply To: GREP style, i want to add "," in numbers 3454342? 3,454,342

Did you read the comments above?

is a word boundary. To make clear, what is excactly a word, there is an article from Marc Autret: https://www.indiscripts.com/post/2011/09/what-exactly-is-a-word
So the GREP will not work at the end of a story. Since every cell behaves like a story, the GREP will fail.

Solution
Do it with 3 steps!

1. Insert something that could be a boundary
Find what: \d\Z
Change to $0~<

2. The FC on the numbers
Find what: \d(?=(\d{3})+)
Change to: $0~<

3. Remove the space at the end of the cell (the story)
Find what: ~<\Z
Change to: nothing

If you work with a GREP-Style instead of FC, don’t do step 3!

best
Kai