Customising field container I've created a cck field formatter. The field outputs uploads from filefield into embedded iframes that link to google docs for display. It currently outputs:

&lt;div class="field field-type-filefield field-field-documents"&gt;
  &lt;div class="field-items"&gt;
    &lt;div class="field-item odd"&gt;
      &lt;iframe src="http://docs.google.com/viewer?url=http://example.com/2011/sites/example/files/session/documents/brighton_online.doc&amp;amp;embedded=true" style="width:470px; height:296px;" frameborder="0"&gt;&lt;/iframe&gt;
      &lt;p&gt;&lt;a href="http://example.com/2011/sites/example/files/session/documents/brighton_online.doc"&gt;Download the document&lt;/a&gt;&lt;/p&gt;        
    &lt;/div&gt;
    &lt;div class="field-item even"&gt;
      &lt;iframe src="http://docs.google.com/viewer?url=http://example.com/2011/sites/example/files/session/documents/sample.pdf&amp;amp;embedded=true" style="width:470px; height:296px;" frameborder="0"&gt;&lt;/iframe&gt;
      &lt;p&gt;&lt;a href="http://example.com/2011/sites/example/files/session/documents/sample.pdf"&gt;Download the document&lt;/a&gt;&lt;/p&gt;        
    &lt;/div&gt;
  &lt;/div&gt;
&lt;/div&gt;


I would like to edit the html outside the contents of the .field-item. Is it possible to do this in the module or do I have to create a custom theme tpl for it?
I'm often using the excellent module Custom Formatters for this kind of purpose. Simple and clean.