column name 'nwt wt' already belongs to this datatable error

Question

I am working on c#

 

I am saving a excel sheet

 

but I am facing an error

 

 

but my requirement is same column name in multiple time in excelsheet

 

below is my original requirement

 

 

what i am doing:

 

datatable data assign to the column

 

see below code:

private void AddStatExcelSheet(DataTable pDT, ExcelWorksheet excelWorksheet)
{
    DataTable dtCust = new DataTable();

    dtCust.Columns.Add("Net Wt", typeof(double));
    dtCust.Columns.Add("sx", typeof(int));
    dtCust.Columns.Add("sd", typeof(double));

    dtCust.Columns.Add("Net Wt", typeof(double));
    dtCust.Columns.Add("sx", typeof(int));
    dtCust.Columns.Add("sd", typeof(double));

    DataTable dt = dr.CopyToDataTable();
    foreach (DataRow Drow in dt.Rows)
    {
        DataRow DRowDetailSubDet =   dtCust.NewRow();
        dtCust["Net Wt"] = Drow["snweight"];
        dtCust["sx"] = Drow["sqty"];
        dtCust["sd"] = Drow["sdweight"];
        dtCust["Net Wt"] = Drow["fnetwt"];
        dtCust["sx"] = Drow["fsx"];
        dtCust["sd"] = Drow["fsd"];
        dtCust.Rows.Add(DRowDetailSubDet);
    }
}

I am trying to add bxc status and fx status but how?

 

please help