Passing Dynamic Variables

I have stored, in a MySQL table, various emails in an html format, the content column being called htmlcontent which is a column text type. I am therefore able to store many different html emails and using dynamic process able to create an email campaign where I can choose the recipients from one recordset and the html email content from another recordset an bam, the email gets sent of to all the recipients no problem.

However, I have discovered that I am unable to do one thing that would really help me, particularly in terms of tracking who opened the email. Lets say in the html email I have a stored in MySQL, I have a link which is laid out something like this when it is pulled in to the page for sending;

<p>some text here</p>

<a href="http://www.mywebdomains.co.uk/emails/january-1.php?readerID=1">Click Here to read this Online</a>

<p>some text here</p>

Note the readerID in the URL link. Is there a way to get UE to echo that id properly as currently, even though I have reference the correct recordset, when the email arrives it shows the link like this;

<a href="http://www.mywebdomains.co.uk/emails/january-1.php?<?php echo readerID=1" ?> >Click Here to read this Online</a>

As you can see it renders the whole echo function not the ID i required. Now, I understand that if I lay html out in the UE dialogue I can include dynamic elements from records sets that are available on the page but, that means I have to created a separate waue_filename_1.php for each email template I created.

I am probably overlooking something here real basic...can enyonw shine a light on a solution for me?