How to update grid cell without reloading complete grid?

Hi,
I have a case where on particular event I have to update a column header and few grid cells.
Presently, I am changing using "gridObj.setHeaderText()" and writing complete object on html using "element.innerHTML = gridObj;"

Issue is it takes lot of time to reflect changes as i am dealing with 20k records.

Is there any way to change header/cell properties, so that we don't have to write complete object on HTML?

you can refresh (repaint) each part individually, for example,

grid.getHeaderTemplate(col).refresh();
grid.getCellTemplate(col, row).refresh();