help with a quantity box and adding a product code to option

Hi Guys,

At the moment I have an item which shows the availability of an stock, such as 'Availability: 100'

What im wondering is whether or not it is possible add more options within the product options box. This way I can add Product Code aswell.

Also the reason I would like to change it is because the customer would currently add 1 item at a time where as if there was a quantity box they could add multiples

I have attached an image.


Any help would be greatly appreciated. I have tried everything

thanks