That is no real problem. Touch interface is just chromium started in kiosk mode with touch interface url. We use a autostart file for desktop to start it at boot up like this:
rm /home/pi/.config/chromium/SingletonLock
chromium-browser --force-device-scale-factor=1 --disable-features=TranslateUI,Translate --app-auto-launched --disable-pinch --noerrdialogs --disable-suggestions-service --disable-translate --disable-save-password-bubble --disable-session-crashed-bubble --disable-infobars --touch-events=disabled --disable-gesture-typing --kiosk --check-for-update-interval=31536000 --remote-debugging-port=9222 http://127.0.0.1:3344/modules/front2/app/app.html &
So just make that as autostart and you should have your touch screen.