Cell formatting when converting from DataGridView to Excel

[rink]

Hi
I need to convert data from Data Grid View to Excel. The below code is doing
that successfully but my problem is I have few columns which have a very long
number (16 characters). When the data is converting until 15th digit the
numbers are correct but the 16th one always convert to zero. I feel I need to
format that cell as "Text" so that it treats the data as Character instead of
Numeric.

Can any one help me how to do it.
My Code:
=======
try
{
// Get the class type and instantiate Excel.
Type objClassType;
objClassType = Type.GetTypeFromProgID("Excel.Application");
objApp_Late = Activator.CreateInstance(objClassType);
//Get the workbooks collection.
objBooks_Late =
objApp_Late.GetType().InvokeMember("Workbooks",
BindingFlags.GetProperty, null, objApp_Late, null);
//Add a new workbook.
objBook_Late = objBooks_Late.GetType().InvokeMember("Add",
BindingFlags.InvokeMethod, null, objBooks_Late, null);
//Get the worksheets collection.
objSheets_Late =
objBook_Late.GetType().InvokeMember("Worksheets",
BindingFlags.GetProperty, null, objBook_Late, null);
//Get the first worksheet.
Parameters = new Object[1];
Parameters[0] = 1;
objSheet_Late = objSheets_Late.GetType().InvokeMember("Item",
BindingFlags.GetProperty, null, objSheets_Late, Parameters);


// Now add the data from the grid to the sheet
for (i = 0; i < datagridview.RowCount - 1; i++)
{
for (c = 0; c < datagridview.ColumnCount; c++)
{
//Get a range object that contains cell.
Parameters = new Object[2];
Parameters[0] = columns[c] + Convert.ToString(i + 2);
Parameters[1] = Missing.Value;
objRange_Late =
objSheet_Late.GetType().InvokeMember("Range",
BindingFlags.GetProperty, null, objSheet_Late,
Parameters);
//Write Headers in cell.
Parameters = new Object[1];

Parameters[0] =
datagridview.Rows.Cells[headers[c]].Value.ToString();

objRange_Late.GetType().InvokeMember("Value",
BindingFlags.SetProperty,
null, objRange_Late, Parameters);


}
}