The best you could do is using a Dictionary to map the column headers with the header you want to use in your csv file.
Something like that:
Dictionary<string, string> headerMap = new Dictionary<string, string>();
headerMap.Add("DGVHeaderText", "CSVFileHeaderText");
Then you would only have to:
StreamWriter csvwriter = new StreamWriter(filename);
cols = cj96TBRiscDataGridView.Columns.Count;
for (int loop = 0; loop < cols; loop++)
{
csvwriter.Write(headerMap[cj96TBRiscDataGridView.Columns[loop].HeaderText] + ",");
}
csvwriter.WriteLine();
Hope this helps.