Hi Massimo,
Thank you for your purchase.

This is not possible with plugin built in features, but someone of our customers made this possible. We did not arrive to test it, so you can try if is working for you.

He actually created a fixed header and column using translation of x and y (no absolute or fixed position used), and here's one solution, take a look:

First of all, you gotta set the z-index for each component below:

jQuery("#table td").css({"z-index": "-1", "position": "relative"});  
jQuery("table tr td:first-child").css({'z-index': '1', 'position': 'relative'});
jQuery("table th:first-child").css({ 'z-index':'2','position':'relative'});

Then you gotta add listener on scroll like this:

jQuery('document').scroll(function () {
   scrollBlock();
});

If your table is set to be scrollable, then you might want to add this in as well:

jQuery('.wdtscroll').scroll(function () {
 scrollBlock();
});

And here's the scrollBlock() part, it is ugly though, but it works for me though. (noted: the numbers work for my theme, if it is not working correctly on yours, then try to adjust the number until it fits.)

function scrollBlock(){
                        var table = document.querySelector('table');
            var top = table.getBoundingClientRect().top;
            top = document.body.className.search('admin') > 0 ? top - 32 : top + 3; // this value can change
            var left = table.getBoundingClientRect().left;
            if(left >= 20){ // before scrolling left (before transforming)
                                if(top >= 0){ // before reaching header bar
                    jQuery("#table_1 thead th").css("transform", "translateY(0px)");
                     translate(jQuery("table th:nth-child(1)"), 0, 0);
                     translate(jQuery("table td:nth-child(1)"), 0, 0);
                                    } else{ // after reaching header bar
                     jQuery("#table_1 thead th").css("transform", "translateY( " + (-top) + "px)");
                     translate(jQuery("table th:nth-child(1)"), 0, -top);
                     translate(jQuery("table td:nth-child(1)"), 0, 0);
                 }
            } else{ // after scrolling left
                                if(top >= 0){
                    jQuery("#table_1 thead th").css("transform", "translateY(0px)");
                    translate(jQuery("table th:nth-child(1)"), -left + 46, 0);
                    translate(jQuery("table td:nth-child(1)"), -left + 46, 0);
                                    } else{
                     jQuery("#table_1 thead th").css("transform", "translateY( " + (-top) + "px)");
                     translate(jQuery("table th:nth-child(1)"), -left + 46, -top);
                     translate(jQuery("table td:nth-child(1)"), -left + 46, 0);
                     }                }
            }
function translate(element, x, y) {
               var translation = "translate(" + x + "px," + y + "px)"
                element.css({
                        "transform": translation,
                                "-ms-transform": translation,
                                "-webkit-transform": translation,
                                "-o-transform": translation,
                                "-moz-transform": translation,
                });
}

It is kind of messy, you definitely can't copy and paste and expect it to work for you. You need to spend some time figuring it out. 

Best regards.

Hi Martina,

We are working on new features of plugin, but for now that feature is not on our TO DO list. Thank you for your suggestion. I  will forward this to my development team to think about this like new feature in future.