i'm allowing the user to export a postgresql db table in .xls format through a php page which contains language translations.

my problem is that the values do not display correctly in the .xls file

i.e. "Algún texto"

i know that i need to set the charset to utf-8 but i'm not sure where. I've adding the header info im sending

PHP Code:
header("Content-type: application/x-msdownload;");
header("Content-Disposition: attachment; filename=tbl_lang.xls");
header("Pragma: no-cache");
header("Expires: 0"); 
if anyone has an answer it would be a great help to me.