CreateProcess() will do it. It has a crapload of parameters, tho. Either look it up in the MSDN help or try this:
If CreateProcess returns 0 (as in res = 0), then the process creation failed. This is very basic as I only recently figured this out. I'd recommend that you read up on CreateProcess().
memset(&pi, 0, sizeof(pi));
memset(&si, 0, sizeof(si));
si.cb = sizeof(si);
int res = CreateProcess("path+executable.exe -parameters", 0, 0, 0, 0, 0, 0, 0, &si, &pi);