Child program manipulation

Is it possible to manipulate a program through some type of child program inside that program. When I say child program, I mean a program that I wrote that would run concurrently with the parent program. If someone has a link for this topic it would be greatly appreciated.

TY B-Con Just couldn't think of a good title at the time =)

But to add to this question, What I am trying to do is to make a mod for a game that I have, and if any of you have ever heard of Red Faction. They have a Myth Trainer that you run at the same time as the game itself and while your playing you can use selected keys on the keyboard to do a specific task, such as, unlimited ammo, invulnerable, and so on. So I'm sure this is possible, But I've tried to do such things and I am coming up short in manipulating the data and most likely going about it the wrong way I'm sure. So I hope this clarifies the question...

This not a poor attempt to make cheats to games, This is my attempt to make programms that are meaningfull to me, so I can practice writing code. If theres no interest than you lose interest, if you know what I mean...

what exactly are you trying to do? I gather that you want to make something similar to Myth Trainer, but what exactly will your program do?

clarification: you don't mean a child program. probably "companion program" is a better term. child program will just confuse people because a child process is a process that another process starts.

Ok, This is what my intent for the program to do. You first open the program that I will create, and in my program code it will list choices such as unlimited ammo, and so on, and make them control buttons,then you will play the game while the other program is running, and for example, you hit "0" and it gives you unlimited ammo, and so on. I hope this helps...

Oh yeah, I guess I called it a child program because when I started this whole thing, I started by just making a menu list that started another program, or the mods that delt with the game. But yes "Companion program" makes better sense, Thx.