//将excel2003转换成excel2007
                  MSExcel.Application excelApp = null;//提要   //word应用程序
                    MSExcel._Workbook excelDoc = null;    //word文档
                    Object nothing = Missing.Value;
                 excelApp = new MSExcel.ApplicationClass();string sourcePath = @"c:\excel2003.xls";      //原文件路径
                 excelDoc = excelApp.Workbooks.Open(sourcePath, nothing,
                         nothing, nothing, nothing, nothing,
                         nothing, nothing, nothing, nothing,
                         nothing, nothing, nothing, nothing,
                         nothing);
                   
                 string targetPath =@"c:\excel2007.xlsx";//导出路径
                 object format = MSExcel.XlFileFormat.xlWorkbookDefault;//转换成新的格式//将新的exccel2007存到本地
                    excelApp.DisplayAlerts = false;//文档转换过程不要出现提示框
                    excelDoc.SaveAs(targetPath, format, nothing, nothing, nothing, nothing, MSExcel.XlSaveAsAccessMode.xlNoChange,
                               nothing, nothing, nothing, nothing, nothing);
                    excelDoc.Close(nothing, nothing, nothing);
                    excelApp.Quit();