Unfortunately, usb programming is not trivial. The universal serial bus is hot plug and play and can work with a massive variety of different devices. When you plug in your usb device, it goes through a process of enumeration that describes to the pc what it does and what driver the pc should load. Device descripters can be quite complex.
One solution for you would be to use a pic microcontroller for the usb interface. You can download a usb stack, free from Microchip, that has a lot of example code for the pic and the pc interface. You should be able to modify the code from the examples to do what you require.