It is possible to change the values of table using a data grid. actually when you change any value in the datagrid, the values will be changed in the base table also.
But it is very difficult (FOR ME IT WAS IMPOSSIBLE) to identify the current row and column number in data grid.
Instead I will say, you should use MSH Flex Grid.
It is more flexible than datagrid.
There are many events of MSHFlexGrid that you can use for the calculation. Only problem is MSHFlex Grid is readonly. So you will need some text boxex to get the data of a current cell of the grid.
After performing the calculations you require, you can copy the data from text box to grid and then from grid to table.
Just go thorugh the events and PROPERTIES of MSHFlexGrid.
You will never want to use DataGrids once you use MSHFlexGrids.
Reply me if you find some better solutions with datagrids instead of MSHFlexGrids. It will be helpful for me too.