PHP code in define pages

[ukgreg]

Newbie with version 1.3.8 (new install)
Addons - 'aboutus'
cart : http://dfwprojectmanagement.com/zencart/
Source: this forum and FAQs.
Yes I did look through FAQs
Yes I did search (if you search for php you get zero results)

Mission:
- Add PHP code to 'define pages'
- Access another database

Summary
We sell online training courses in several modules. At the end of each module the user can take a quiz. I want them to return to zencart, log in, then navigate to the page 'My Courses' (renamed from page_2) and the quiz will be displayed. My quiz questions are stored in another database on the same web host (and I do know how to write code to access 2+ databases).

Problems
- PHP code not working

Now I've typed in PHP code into the 'define pages editor' and direct into the php source code to no effect. I feel very dizzy from all these overrides and I'm sure there is something not 100%.

However, is my basic objective possible? or is this a case to use EZPages to an external URL? IF so how do I keep track of ZenCarts session variables? I will need (at least) the customer id to determine which quiz the user needs.

Can you direct me to other articles where this is covered?

Thanks

[yellow1912]

Did you open php tag?

<?php code here ?>