Vista - Writing special characters to excel html

Having some trouble writing out accented characters to an ms-excel
type output from my asp.net page (c#).
I've tried a few different charsets but every time the è on my page is
getting rendered as è

Any ideas?

...
Response.Clear();
Response.Buffer= true;
Response.AddHeader("content-disposition",
"attachment;filename="+filename+".xls");
//Response.AddHeader("charset", "ISO-8859-1");

Response.ContentType = "application/ms-excel";
//Response.ContentType = "application/ms-excel,ISO-8859-1";

Response.Charset = "";
//Response.Charset = Encoding.UTF8.EncodingName;
//Response.Charset = Encoding.Default.EncodingName;
//Response.Charset = "ISO-8859-1";
...

Found this similar post, but it doesn't have any resolution listed.
http://groups.google.com/group/micro...+%2B+ms-excel#