How to convert an xlsx file to a CSV in c++ qt?

Question

I am working on a project where I have to make a table from an excel file. The following code that is related to making a table from a CSV file, works fine. How can I convert my excel file to CSV in this code, in order to have a table from my excel file? Also, is there another way to make a table from an excel file, without converting it to a csv file?

I have used QFile to import my excel file.

I would appreciate if someone could help me on this matter. Here is the code:

Mainwindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QStandardItemModel>

namespace Ui {
class MainWindow;
 }

class MainWindow : public QMainWindow
{
 Q_OBJECT

public:
   explicit MainWindow(QWidget *parent = 0);
   ~MainWindow();

private:
   Ui::MainWindow *ui;
   QStandardItemModel *csvModel;
};

#endif // MAINWINDOW_H

Mainwindow.cpp:

#include "ui_mainwindow.h"
#include <QFile>
#include <QTextStream>
#include <QDebug>


MainWindow::MainWindow(QWidget *parent) :
   QMainWindow(parent),
   ui(new Ui::MainWindow)
  {
     ui->setupUi(this);

    csvModel = new QStandardItemModel(this);
    csvModel->setColumnCount(3);
    csvModel->setHorizontalHeaderLabels(QStringList() << "Header1" << "Header2" << "Header3");
    ui->tableView->setModel(csvModel);


   QFile file("C:/Users/Haybert/Desktop/test.xlsx ");

   if ( !file.open(QFile::ReadOnly | QFile::Text) ) {
       qDebug() << "File not exists";
    } else {

    QTextStream in(&file);

    while (!in.atEnd())
    {
        QString line = in.readLine();

        QList<QStandardItem *> standardItemsList;

        for (QString item : line.split(";")) {
            standardItemsList.append(new QStandardItem(item));
         }
          csvModel->insertRow(csvModel->rowCount(), standardItemsList);
      }
      file.close();
   }
  }

   MainWindow::~MainWindow()
   {
     delete ui;
     delete csvModel;
    }