Vim search and replace

Vim allows proficient search and replace with the :%s command.

Select until nth occurence of a pattern

Non-greedy behaviour: use .{-} instead of the more common regex operator .*?.

Here as an example, select all until the second occurence of a , character, and replace it with the same (&) but adding the word test :

:%s/\(.\{-},\)\{2\}/&test/