I am trying to have number bullets in Excel. I am able to use the function
concatenate, but it does not increment the numbers, such as

1
1.1
1.1.1, 1.1.1, 1.1.1 (I need 1.1.1, then 1.1.2, and 1.1.3).
This is an example of what I am using =CONCATENATE($B$4,".",$I$2). The $B$4
value is 1.1 and $I$2 value is 1

Is it possible to do in excel?