If you want to add a block into cms page, you just have to add this into its content

{{block type="adin_page/page_html_combos" name="combos" template="page/html/combos.phtml"}} 

Of course, don’t forget to create the block class app/code/local/Adin/Page/Block/Page/Html/Combos.php

class Adin_Page_Block_Page_Html_Combos extends Mage_Core_Block_Template
{
//...
}

and the .phtml file
app/design/frontend/adin/default/template/page/html/combos.phtml

But when you want to render the page, nothing.
On the logs (system.log), you have : Security problem: adin_page/page_html_combos has not been whitelisted.
It’s a new feature since securoty Patch SUPEE-7405 and Magento CE 1.9.2.2, you have to add your block into whitelist. You can do it manually, in backoffice, System > Permissions > Blocks or do it programmatically :

$blockNames = array(
    'adin_page/page_html_combos'
);
foreach ($blockNames as $blockName) {
    $whitelistBlock = Mage::getModel('admin/block')->load($blockName, 'block_name');
    $whitelistBlock->setData('block_name', $blockName);
    $whitelistBlock->setData('is_allowed', 1);
    $whitelistBlock->save();
}