I don't know the exact code for this, but I can tell you one way to get it. Find a release that has "Player Exchange" shop, like "Endeavor" and see the stuff they use. They ask you to input a String/Integer, and then something is executed depending on what you entered and the value that code was given. I have done several like this but I believe you are using a PI, so me providing that code won't help in any way. :/