How can I send a message to cmd

[C# Programming]

Hi guys ...
I was looking for a way that allow me to send a message to cmd directly ... , I've searched about an answer, but I didn't find what I want.
I want my windows Form to send messages to CMD without open a new one
I mean it's already opened on my PC but I want a way to send messages only .. So can I do that ?

I think I'll need DllImport or something like that to get it work

Thanks for your help ..