Bypass load form & Passing Values to called program textbox & click btn

Question

Good day, I got calling another program working.
string root = Application.StartupPath;
string exePath = System.IO.Path.Combine(root, "i:\\app\\test\\WAREH004.exe");
string argPath = System.IO.Path.Combine(root, "i:\\app\\test\\WAREH004.INI");
Process.Start(exePath, argPath + " 1");
I need help:
The program i'm calling has the same load form that the current one uses.
1. How do i bypass the load form & load the main form with the forms values i selected on the current program?
2. How do i also pass values to the called programs textbox & click a button?

Please Assist!