How to sort column containing chapter value (1.1, 1.2...,1.10)

Hi,

I'm faced with a "problem" to sort values in a column that contain chapter values (think of it as a book) when I sort/order them with 'order': [[0, 'asc']], I get this order:
-1.1
-1.10
-1.11
-1.12
...
-1.2

But obviously that's not what I want I want:
- 1.1
- 1.2
- 1.3
- ....
- 1.10
- 1.11
- 1.12
- ...
- 1.19
- 1.20

Any hint on how to achieve that ? I was able to find a ugly "hack" by adding an extra hidden column and splitting 1.1 into [1] [0][1] , 1.11 into [1][0][11] and 1.2 becomes [1][0][2] and so on... but that can't be the right way