Write cmd via shellExecute, system or createProcess

[JChomp]

Hi everyone,

I need your help. I am working on an optimization process. To do so I‘ve made a program that executes another program (.exe). I can open it without any problems using 3 different methods system, shellExecute and CreateProcess. But I have not succeed to write command lines in the called program via mine. The program I run with mine has no UI, it is just cmd line.
Which one of these 3 methods is the best to write command lines on the other program and how can I do that?
Hope you can help me. I’ve tried lots of ways but I cannot found any solution.

Thanks!
JC