I tried Googling this, but can't get the wording just right.

We currenly have a C program that runs at a DOS prompt, err, Powershell, excuse me.

When it starts the DOS window opens, after that we can type in additional commands.

We're going to put a GUI front end on it. I'm familiar with starting a program, but who do I get additional commands to the program after it starts, i.e. typed into the DOS box, hit "enter."

That's it, and any info is appreciated.

Aris

Powershell scripts are usually started by:

powershell.exe name-and-path-of-script.ps1

So simplest way could be to hardwire any GUI buttons to predefined ps1-files.