Podíjte se, prosím Vás, na funkci CreateProcess
https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessa

Zkuste si maly program, ktery spousti notepad.exe s parametrem pokus.txt

#include <iostream>
#include <windows.h>
 
using namespace std;
 
int main (int argc, char * * argv)
{
	cout << "Start" << endl;
 
	STARTUPINFO startup;
	memset (&startup, 0, sizeof (startup));
 
	PROCESS_INFORMATION info;
	BOOL ok = CreateProcess
        ( 
	 NULL, //  LPCTSTR lpApplicationName,
         "notepad pokus.txt", // LPTSTR lpCommandLine,
         NULL, // LPSECURITY_ATTRIBUTES lpProcessAttributes,
         NULL, // LPSECURITY_ATTRIBUTES lpThreadAttributes,
         FALSE, // BOOL bInheritHandles,
         0, // DWORD dwCreationFlags,
         NULL, // LPVOID lpEnvironment,
	 "c:\\work", // LPCTSTR lpCurrentDirectory,
         & startup, // LPSTARTUPINFO lpStartupInfo,
         & info  // LPPROCESS_INFORMATION lpProcessInformation
   	);
 
	return 0;
}

Zde je kompletni program Create Process