Finding a colSpan Header for one of the cells or td's is Spans

Question

I have multiple column headers that spans of multiple column and I would like to find the correct header number/count for the columns.

I want to enter a column numbe

Answer 1

That's easy, as long as you don't have any rowspans:

function getCell(tr, col) {
    var cell = tr.firstElementChild;
    while (cell && (col -= cell.colSpan || 1)>=0)
        cell = cell.nextElementSibling;
    return cell;
}

See demonstration.