I'm not exactly sure if I understood your question, but here's my shot:
Code:
int seed = someNumber;
srand(seed); // Set the seed
cout << rand() <<endl;
cout << rand() <<endl;
cout << rand() <<endl;
If you execute this program several times, you will have the exact same output.
So the rand() function gives random numbers in a sequence, based on a seed.
If you want random sequences, you will have to use a "random" seed.
You can do this by, for example, using the current time as the seed.
For more info, see:
rand - C++ Reference