List object 's selected cells value capture in excel 2007 using vsto 3.0

Question

Hi All,
Here i m trying with listobject control in excel 2007..here i took one list control and made database fields to populate in list..

What i need is i want to update the database directly when we update the cells in list control in excel..

for that i need to capture the cell which is modified...
for that firstly i'm capturing rownumber and then through that rownumber i want to find the value which is modified and i need to update the datbase directly...

hope everyone understand this..
Here is my code... 


int i= list1.SelectedIndex;
  string x = "A" + i.ToString();
  string y = "B" + i.ToString();
  var cell = list1.Range["Type.Missing", y];
  string p = Convert.ToString(cell);

I know that P value shows error...
but i want to know the cells value here by any means..