No.
Step #1) Attack with Riposte Strike. Do whatever you'd like with your remaining actions. Your turn ends.
Step #2) The monster you hit might attack you. If he does, you immediately get to attack him. You attack occurs before the monster's attack. After you've resolved your immediate interrupt, the initiative order resumes as normal.
Step #3) Eventually, your turn comes up again in initiative, and you can do whatever you want.
EDIT: Put another way, it doesn't matter if your target attacks you before others attack you. That's irrelevant. "Winning Initiative" isn't relevant either.
In my turn to attack.And I attack someone who has already had his attack.As he had a better initiative roll.Using Riposte Strike does nothing ?