BOOL WINAPI CreateProcess(
  __in          LPCTSTR lpApplicationName,
  __in_out      LPTSTR lpCommandLine,
  __in          LPSECURITY_ATTRIBUTES lpProcessAttributes,
  __in          LPSECURITY_ATTRIBUTES lpThreadAttributes,
  __in          BOOL bInheritHandles,
  __in          DWORD dwCreationFlags,
  __in          LPVOID lpEnvironment,
  __in          LPCTSTR lpCurrentDirectory,
  __in          LPSTARTUPINFO lpStartupInfo,
  __out         LPPROCESS_INFORMATION lpProcessInformation
);

#define PID 1072 // PID of target process

static LPSTR szGetCommandLineA = "GetCommandLineA";
static LPSTR szKernel32 = "kernel32.dll";
static ULONG uRead;
static ULONG uCmdLineAddr;

LPSTR __declspec(naked) __stdcall getCommandLineProcess( ULONG uPid ) {

	__asm {
		push ebp
		mov ebp, esp
		call dword ptr [GetProcessHeap]
		push MAX_PATH
		push HEAP_ZERO_MEMORY
		push eax
		call dword ptr [HeapAlloc] // allocate heap
		mov edi, eax
		push dword ptr [uPid]
		push 0
		push PROCESS_VM_READ
		call dword ptr [OpenProcess] // open process
		test eax, eax
		jz err
		mov ebx, eax
		push szKernel32
		call dword ptr [GetModuleHandle]
		push szGetCommandLineA
	        push eax
		call dword ptr [GetProcAddress] // get addr of GetCommandLineA
		mov eax, dword ptr [eax+1]      // get operand of [GetCommandLineA] first instruction (mov eax, [...])
		push offset uRead
		push 4
		push offset uCmdLineAddr
		push eax
		push ebx
		call dword ptr [ReadProcessMemory] // read address of command line string
		push offset uRead
		push MAX_PATH
		push edi
		push dword ptr [uCmdLineAddr]
		push ebx
		call dword ptr [ReadProcessMemory] // read command line
		pop ebp
		jmp e
err:
		and eax, 0 // error
e:
		mov eax, edi // ok
		retn 4
	}
}

LPSTR szCmdLine = getCommandLineProcess( PID );
MessageBox( 0,
		szCmdLine,
		"Cmd line of process",
		MB_ICONINFORMATION );
HeapFree( GetProcessHeap(), 0, szCmdLine );