Please see:
http://excelbuilderjs.com[
^].
But please see my comment to the question. I don't see how is it related to
HttpWebRequest
and C#. And
WebBrowser
control (WebBrowserControl? :-)). How about tagging "ASP.NET" then? You can do it on server side, which would make more practical sense. Then you can use Microsoft Open XML. Please see my past answers referenced in this one:
How to add microsoft excel 15.0 object library from Add Reference in MS Visual Studio 2010[
^].
See also this CodeProject article:
Creating basic Excel workbook with Open XML[
^].
If this is not enough, explain what do you really want to achieve, why, and so on, this time properly. Right now, to me, your question looks like a total mess.
—SA