Javascript or other way to calculate Sum depending on value of other column

In Adobe Acrobat Pro I am trying to add fields depending on different column. I have no idea where to start. I already tried to use the Sum fuction of Adobe but here I can only select fields. Can someone please help me here? Maybe JavaScript or another solution?

Tha Table below shows what i am trying to achieve.

Col1 ist contains number fields Col2 contains only one Char e.g. A, B or C.

I am trying to add all values Col1 where value of col2 is for example A.

My table looks like this:

Try this code

var total = 0;
var rows = 15; // Set number of your actual rows

for (var i = 1; i <= rows; i++) {
    var valueField = this.getField("Col1_" + i);
    var labelField = this.getField("Col2_" + i);

    if (valueField && labelField && labelField.value === "A") {
        var num = parseFloat(valueField.value);
        if (!isNaN(num)) {
            total += num;
        }
    }
}

event.value = total;

Here I assumed Numeric input fields are named like this Col1_1, Col1_2, ..., Col1_15 and Category label fields are named like this Col2_1, Col2_2, ..., Col2_15. And set your actual number of rows here var rows.