obj.getDataProperty and setDataProperty

Help !!!!!

when I cycle through my grid, I wanna move all cells to the right.
To get the values is no the problem, but how can I write them to the lefthanded cell ?

I tried the following:

for(i=0; i<obj.getRowProperty("count");i++) {
   for(j=obj.getColumnCount()-2;j>0;j--) {
      val = obj.getDataProperty("text", i, j);
   }
}

but how can I write it to row(i)/column(j+1) ???

I have really no clue.
btw. The sorting is different from the array i feed the grid with.

Help please