Fixed columns number on the scroll viewport

Onotole

So here's my case, I have a big table, with.. say... 7 columns with a horizontal+vertical scroll, first row and first column fixed.

$('.my-table table').DataTable({
        scrollY: "300px",
        scrollX: true,
        ordering: false,
        paging: false,
        info : false,
        filter: false,
        autoWidth: false,
        fixedColumns: {
          leftColumns: 1
        }
});

So far this works for me very well. However what I do need is configure the table to have fixed column width with 25% width of the view, which means only 4 columns seen by default, rest of them is hidden beyond the scroll (See attached image):
- Once the page is opened - the user will only see 4 columns (1st one with the labels, fixed + 3 columns with data)
- maintain fixed cells & scrolls

Please help me out with this one, none of option helped me so far, probably I'm doing it wrong