Download Excel file with bold header with array input using

Question

Am downloading an excel file by giving array input and with static headers. Here is my code snippet:

function exporttoexcel(data){
var tmpArr = [];
var tmpArr2 = [];
var csvData = [];
tmpArr2.push("SCA Number","Contract(Project) Name");
csvData.push(tmpArr2.join('\t'));
for(var i=0;i<data.length;i++){
tmpArr = [];
tmpArr.push(data[i].Title);
tmpArr.push(data[i].ContractName);
csvData.push(tmpArr.join('\t'));
}
var output = csvData.join('\n');
SaveContents(output);}

File download is working fine. My issue is to get the headers in excel file as bold, in the downloaded file. Anyway, I can achieve it by placing the data in HTML tags.But, I have to generate using array input. Can anyone suggest a better solution for this issue???