How to have rowspan/colspan and javascript data

Hi,
I have this situation where I want to use DataTable to display livestats.
First, there is one ajax call that get the table column list and some are embedded to other (ie, we should use rowspan and colspan)
So, how can we provide columns list in the form
[{name: column1},
{name: column2},
{name: column3, columns:[{name: column31}, {name: column32}, {name: column33}]
},

So, column31, column32, column33, are under column3.

I tried to build the header in HTML. But if I do so, then I have issues with data which comes as ajax object as well.

Thanks,