Set value to sum grid cells and disable others

I have a grid which has one combo cell and 2 editables cells. when i put some value on the 1 editable cell i want the next one to disable and the value of the first cell lets assume its on (1,1) to be copied at (2,2) and (2,1) to be disabled and vice versa. I tried to do that with the editoncell function but it doesnt work. Any help?


Here you can find the example of the solution: