I have also tried to use Book.SaveAs(filepath) . It is giving an error -- 'Cannot access read-only document 'dealImports.xlsx'. Please refer the code. The function has few parameters.
function updateExcel(fileName, sheetName, arrayStartDate, arrayEndDate) {
var book;
var filepath=Project.Path+fileName;
var app1 = Sys.OleObject("Excel.Application");
app1.DisplayAlerts = false;
book = app1.Workbooks.Open(filepath);
var sheet = book.Sheets(sheetName);
var rowCount = sheet.UsedRange.Rows.Count;
Log.Message('Row Count '+rowCount);
var j=0;
for(var row = 2; row <=rowCount+1; row++) {
Log.Message('Trade Start Date -- '+arrayStartDate[j]+ ', Trade End Date --' +arrayEndDate[j]);
sheet.Cells.Item(row, 7).Value = arrayStartDate[j];
sheet.Cells.Item(row, 8).Value = arrayEndDate[j];
if(row==arrayStartDate.length+1) {
break;
}
j=j+1;
}
book.Save();
app1.Quit();
}