Form action resulting in 404

Hi All,
First of all thanks to all those wonderful people out there who take time out and help !!

I am using the wp-pro-quiz plugin. This plugin lets the administrator create a quiz and add questions to the quiz. So, the quiz has a URL

/wordpress/wp-admin/admin.php?page=wpProQuiz&action=addEdit

I want to give this functionality to all the subscribers also. So, I changed “wp-admin/admin.php” to the page where I want this quiz to be displayed(which worked fine for me). At the bottom of the page, there is a save button which is redirecting to admin.php page on saving:

<form method=”post” action=”admin.php?page=wpProQuiz&action=addEdit&quizId=<?php echo $this->quiz->getId(); ?>”>

If I replace the admin.php to the my page, it gives me the 404 error.

Can anyone suggest what I am missing or doing wrong?

Thanks for your time.

Siloni