C++ :: How To Restrict User To Enter Four Digit Number Only

I am trying to write up something to have a user to enter a four digit number. Only four digits, Ex: 0001, 0116, or 9999. There is no getting around the selection 0001 or 0002. I understand if not done correctly, the first three 0's will be ignored.

I've been just playing around with what I have below but I just don't remember how to do it nor can I find a good example online to figure it out. I know it is not correct just typing to try to remember. I am aware that it is gibberish right now, this is just me brainstorming.

int number;
cout<<("Please enter the four digit number(Ex: 0001):
");
cin>> setw(2) >> number;
cout<<)"Please enter four digit date. Two digits for month and two digits for year:
");
cin>> date;
if (number< || number > 30)
cout << "Invalid choice. Try again." << endl;
cin.clear();