Thanks this is perfect, now lets say that I execute the rybka engine and run it in the background so there is no command window to execute these, is there a program or code to send to commands to a rybka process already running without having to create a new process. Here is the setup I have: A gui program accesses rybka, example Arena, so now I open task manager and notice that the rybka process is there because that is the default engine, now say instead of using the gui's settings menu I wanted to use another program to send commands to the same process, I want to do this to maximize analysis in a 5 minute game, so a seperate program determines the severity of the position, and determines how much time to alot Arena to analyze the position by changing the rybka.exe processes settings.