windows - run the same exe with different argument simultaneous in c++ -

does have idea open same exe file different arguments @ same time in c++.
in past, open multiple commend line in windows run exe simultaneously,
however, seems not best way solve it. hence try implement in c++ automatically run multiple processing @ same time.
have tried this, still can not work....
problem:
e.g. run
1. a.exe -dir d: -num 1000
2. a.exe -dir d: -num 1500
3. a.exe -dir d: -num 2500
@ same time in c++.

(answered op in edits. see question no answers, issue solved in comments (or extended in chat) )

the ops solution is:

sol:

std::ostringstream trainsamplescmd[2]; trainsamplescmd[0] << "a.exe -data cascade/1 -vec vec/test.vec -bg neg.txt -numpos 1000 -numneg 1000 -w 30 -h 14"; trainsamplescmd[1] << "a.exe -data cascade/2 -vec vec/test.vec -bg neg.txt -numpos 1500 -numneg 1000 -w 30 -h 14"; for(int = 0; < 2; i++) {         startupinfo si;         process_information pi;      zeromemory( &si, sizeof(si) );     si.cb = sizeof(si);     zeromemory( &pi, sizeof(pi) );     if( !createprocess( null,   // no module name (use command line)         const_cast<char *>(trainsamplescmd[i].str().c_str()),        // command line         null,           // process handle not inheritable         null,           // thread handle not inheritable         false,          // set handle inheritance false         0,              // no creation flags         null,           // use parent's environment block         null,           // use parent's starting directory          &si,            // pointer startupinfo structure         &pi )           // pointer process_information structure         )      {         printf( "createprocess failed (%d).\n", getlasterror() );         system("pause");         return 0;     } }