Look for GetObject or ActiveXObject for JavaScript.

ActiveXObject example :


var handle= new ActiveXObject("Excel.Application");
var handle_file = handle.Workbooks.Open("excelfile.xls");
var handle_sheet = handle.Worksheets("SheetName");
data = handle_sheet.Cells(1,1).Value;

GetObject Example :

var handle= GetObject("excelfile.xls", "Excel.Application");
var handle_sheet= handle.Workbooks("SheetName");
data = handle_sheet.Cells(1,1).Value;

You should define excel file location exactly same as it locates on server