You can adjust the Python code in this folder to convert WordPress style caption tags

[caption id="attachment_69281" align="aligncenter" width="229"]
    <a href="http://martin-thoma.com/wp-content/uploads/2013/06/amazon-double-domination.jpg">
        <img src="http://martin-thoma.com/wp-content/uploads/2013/06/amazon-double-domination-229x300.jpg" 
             alt="Amazon doesn&#039;t like band no. 4 of &quot;The Dresden Files&quot;" 
             width="229" height="300" class="size-medium wp-image-69281" />
    </a> Amazon doesn't like band no. 4 of "The Dresden Files"
[/caption]

to my caption tags

{% caption align="aligncenter" width="229" 
    caption="Amazon doesn't like band no. 4 of 'The Dresden Files'" 
    url="../images/2013/06/amazon-double-domination.jpg" 
    alt="Amazon doesn&#039;t like band no. 4 of &quot;The Dresden Files&quot;" 
    height="300" 
    class="size-medium wp-image-69281" 
    title="Amazon doesn't like band no. 4 of 'The Dresden Files'" %}

This is not necessary for my plugin, but it “could come in handy some day” :-)