No difference in the 2 cases between:
(?<=\d) (?=\d{3}\>)
(?<=\d) (?=\d{3})
On ID CC and ID CS4 (Mac)
The 2 Grep fail on:
Product A56Z1 324.45
As I've already written, I often use NJ to fix this kind of problem: if we insert a NJ here (using a first grep research to treat this point):
Product A56Z1[NJ] 324.45
and use this grep:
((?<=\d[^])|(?<=\d))( )(?=\d{3})
it seems to work: Product A56Z1[NJ] 324.45 is not taken in account and the space between "1" and "3" is not replaced by a comma.