Thank you all for your replies,

I really have to do it, i don't have choices. It doesn't matter to be reliable.
So i want to ask these questions:

1) How long may it take?
2) For only to run this c++ program. i don't need any other peripherals (no VGA, keyboard..). i have engineering background but without practical experience. how should i start?

What i understand that i have 2 options:
1) Use a RTOS and C++ compiler for the processor (for example 386 intel compiler). and an Ethernet chip to be as I/O port to the processor.

2) To have an OS like Windows CE, and use the C++ code directly with a c++ embedded environment.

Am i right? please let me know if i'm not.

Do you have any suggestion for the right option.

Thank you.