How to export data in excel with few column from gridview not all column?

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ASP.NET

SQL

I want to Export Some colmn data from grid Not All .
For Example : id,name,email,delete,edit (this is grid column)

but I need: Name,Email

NOT All Data.

What I have tried:

Response.Clear();
Response.AddHeader("content-disposition",string.Format
("attachment;filename={0}.xls",fileName));
Response.Charset = "";
Response.ContentType = "application/vnd.xls";
StringWriter stringWrite = new StringWriter();
HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
GridView1.RenderControl(htmlWrite);
Response.Write(stringWrite.ToString());
Response.End();