Change cck field to '#type'='hidden'?

Issue Summary

Hi! I'd like to dynamically hide a CCK textarea field, based on some logic around user permissions and arguments passed into the edit form.

Here what I'm trying this in node-form.tpl.php:

...But the textarea is still returned as part of $standard, and also in $field_note.

Any suggestions or advice would be great appreciated -- thanks in advance!