hide all of node form except a file upload field Bit of a weird one....

I'd like to call a node edit form into an overlay but have it only show a file upload (cardinality unlimited) fieldset and the save button

I know I can program the formAPI bits, get the files and save the node myself, but In this (possibly strange) case I'd like to use the existing form.

Obviously can CSS it, but I'd rather have it in PHP. 

So far I've set up a loop in a conditionally invoked form alter that finds form elements and then... well, unsetting/hiding them gets them off the screen but then the upload field doesnt work

foreach($form as $key =&gt; &amp;$value) {
  if(is_array($value) &amp;&amp; isset($value['#type'])) {
    if(  !in_array($value['#type'], array('hidden', 'value')) 
      &amp;&amp; !in_array($key, array('field_my_file_field', 'actions'))) {
      unset($form[$key]);
      //or $form[$key]['#type'] = 'hidden';
    }
  }
}


I'm guessing I'm compromising the form array, so it's not working in a callback somewhere. 

Any ideas? Or a better suggestion for getting just the field upload fieldset onto a page?

Thanks!
You can use Field Permission module to hide all those fields which you don't want to show on node edit or node create form for all user type which you want.