Using any kind of php inside your content is something we should try to avoid at all times but, sometimes due to design you're forced to do what you don't want to.
Unfortunately I was forced to embed a block within content and found a few pages that helped me get what I needed to embed a block.
<?php //D7 $block = module_invoke('module_name', 'block_view', 'block_delta'); print render($block['content']); ?>
Definitions for Module Name and Block Delta and where to find those variables:
'module_name' = The machine name of the module (i.e. the module's folder name). This is true for core modules too, so for instance 'search', 'user' and 'comment' would all work here.
'block_delta' = The machine name of the block. You can determine what this is by visiting the block administration page and editing the block. The URL for editing a webform block, for instance, would be something like:
Drupal 7: admin/structure/block/manage/webform/client-block-11/configure
Drupal 6: admin/build/block/configure/webform/client-block-11
In this example, 'webform' is the module name and 'client-block-11' is the block's delta.
Drupal 7: admin/structure/block/manage/is_scorecard/initial_form/configure
<?php //D7 $block = module_invoke('is_scorecard', 'block_view', 'initial_form'); print render($block['content']); ?>
More info can be found here: drupal.org