dont round number in excel

hello
i send the result of search to a radGridView1, and radGridView1 to Excel.
but i dont show numbers currectly. i round the number in excel. for example the number 12.34 will be shown to 12. but i wants to show as sama as it is.
below is the code:
thanks very much.

object[,] array_data = new object[rows_count, nCols];
range_data = worksheet.get_Range("A3", Convert.ToChar(65 + nCols - 1 ) + (nRows + 2).ToString());





i = 0;

for (int k = 0; k < nCols; k++)
{
int h = 0;

for (int j = 0; j < radGridView1.RowCount; j++)
{

if ((radGridView1.SelectedRows.Count <= 1) || (radGridView1.Rows[j].IsSelected == true))
{
range_data[h + 1, k + 1 ] = radGridView1.Rows[j].Cells[k].Value;
h++;
}
}

i++;
}