How to Find/Replace (also using Wildcards)

This is somewhat of a two-parter. I have an XML file that has many lines that look like this:

<something id="54875" source="something.me">
<code>./random/text/here.html</code>
<morecode>./more/random/text/here.html</morecode>
</something>

This snippet above repeats sevearl hundred times. I need to find all the instances where the <code> and <more> lines apear, then add a third line under it so it looks like this:

<something id="54875" source="something.me">
<code>./random/text/here.html</code>
<morecode>./more/random/text/here.html</morecode>

<addedcode>./added/random/text/here.html</addedcode>
</something>

Furthermore, each snippet has unique text between the brackets. So I'll need to use a wildcard so it ignores anything written inside the <code> and <more>, so I can go line by line copy/pasting the replacment text.

How can I easily do this in Dreamweaver (or another app if needed)?