I have a Final Project assignment that I am trying to complete ahead of time. The problem I am running into is how to call a Visual Studio 2012 C++ function inside the html code so that it will output the order cost of an item based on the quantity in a table. All of the code output creates a webpage receipt. Here is the code I have so far. I am not asking to have it solved but instead be pointed in the right direction.
A receipt should summary of an actual order, it only serves as output. You don't need to call any C++ functions from within the HTML. The only way to do so would be to have a (web)server installed which you could communicate with through a (asyncronous) HTTP GET or POST. On microsoft platforms, using C++ or C#, this is usually done using ASP.NET (active server pages).
Anyway, a receipt is not an order-form where the user enters data, submits it and then gets a receipt. It only serves as a summary for the data you have available within the C++ program.
If you mean to say that you want to insert the result of a calculation into the recept_in_html string, you can use simple concatenation: