How to run external Application in WordPress

Hi all,
I am looking for my custom solution in WordPress. I need my external application (Example: http://www.example.com/Bookingapplication.php) runs in my WordPress website. If I use iFrame tag and put the URI of my website in it, two scrollbar are appears which is not look good, but application works fine. I do not want to redevelop my application for WordPress. I have tried to create custom form and table with the help of this sample: Custom Table

Also, I review the plugin call Custom Database Applications by Caspio and they offering all what I am looking for, but I am not wants to use there server and database.

Thanks in advanced.

-MAK