I have an index controller with a view action that does the following:

echo $this->getLayout()
    ->createBlock('core/template','builder')
    ->setTemplate('pages/builder/view.phtml')
    ->setHeaderText($extra->getHeaderText())
    ->setFooterText($extra->getFooterText())
    ->setProducts($collection)
    ->toHtml();

Based on this, I am trying to perform layout updates in builder.xml (which is being set in the module's config.xml). However, I am not sure if you can target blocks instantiated in this manner. Based on the above block creation, am I able to perform the following:

<layout version="0.1.0">
    <builder_index_view>
        <!-- shouldn't this reference the createBlock() name argument? -->
        <reference name="builder">
            <block type="page/html_header" name="builder.header" as="builder.header" template="pages/builder/header.phtml"/>
        </reference>
    </builder_index_view>
</layout>