How to design a control window to control DE2 through DM9000?

Hello, I want to design a control window on PC by VC or VB to control DE2 through DM9000. But I don't know how to realize it?

I knew the DE_NET demostration clearly. I can send or receive normal data between PC and DE2 through DM9000.

But now I want to design a window on PC. If I clicked one button on the window, it will give message to Nios II through DM9000, and one led lighted at last. Counld somebody help me how to realize this function, please?