Cacher is the code snippet organizer for pro developers

<?php
	include 'app/Mage.php';
	Mage::app();

	$_codes = array('l_w_h');

	$attSet = Mage::getModel('eav/entity_type')->getCollection()->addFieldToFilter('entity_type_code','catalog_product')->getFirstItem(); // This is because the you adding the attribute to catalog_products entity ( there is different entities in magento ex : catalog_category, order,invoice... etc )
    $attSetCollection = Mage::getModel('eav/entity_type')->load($attSet->getId())->getAttributeSetCollection(); // this is the attribute sets associated with this entity
	$order = 0;
	foreach($_codes as $code){
		$attributeInfo = Mage::getResourceModel('eav/entity_attribute_collection')
					->setCodeFilter($code)
					->getFirstItem();
			$attCode = $attributeInfo->getAttributeCode();
			$attId = $attributeInfo->getId();
			foreach ($attSetCollection as $a)
			{
					$set = Mage::getModel('eav/entity_attribute_set')->load($a->getId());
					$setId = $set->getId();
					$group = Mage::getModel('eav/entity_attribute_group')->getCollection()->addFieldToFilter('attribute_set_id',$setId)->addFieldToFilter('attribute_group_name', 'Eigenschaften')->getFirstItem();
					$groupId = $group->getId();
					$newItem = Mage::getModel('eav/entity_attribute');
					$newItem->setEntityTypeId($attSet->getId()) // catalog_product eav_entity_type id ( usually 10 )
										->setAttributeSetId($setId) // Attribute Set ID
										->setAttributeGroupId($groupId) // Attribute Group ID ( usually general or whatever based on the query i automate to get the first attribute group in each attribute set )
										->setAttributeId($attId) // Attribute ID that need to be added manually
										->setSortOrder(90 + $order) // Sort Order for the attribute in the tab form edit
										->save()
					;
					echo "Attribute ".$attCode." Added to Attribute Set ".$set->getAttributeSetName()." in Attribute Group ".$group->getAttributeGroupName()."<br>\n";
			}
			$order = +10;
	}