I use data:application/vnd.ms-excel to make excel,but when I use it ,the typeface is always be Arial Unicode MS ,I want to change to other typeface,how can i do?

        var uri = 'data:application/vnd.ms-excel;charset=UTF-8;base64,',
        base64 = function(s) { return window.btoa(unescape(encodeURIComponent(s))); },