How to modify a cck field of Node A when Node B (referenced from Node A) is modified Drupal 6 Question: 

I have two content types - a Property and a Task. The Task content type has a CCK Node Reference field that references the Property node it belongs to. When I modify a certain field in the Property node, I need to automatically update the "field_task_status" within it's referring Task node to "Complete". 

I've been able to accomplish this with Rules 1 and VBO, but It seems like building a multitude of VBO views and triggered rules just to handle switching the Task node's status to "complete" or "pending" is a bit overkill. 

Is there a more efficient way of doing this through a small custom module? I've heard that VBOs are heavy on the server, and I don't want to run into problems with the VBOs bogging down site.

I was initially thinking that I could write a query to get the nid of the referring Task node, and use that to load that Task and subsequently modify the value of its "field_task_status" ... I'm not a developer by trade, but I can put the code together if I have some idea of where to start. 

Edit: Here's my attempt at coding a custom module, it's not getting me what I want...am I even close?

function mymodule_task_updater($property)
{
 $task_id =db_result( db_query( 
 "SELECT tn.nid FROM content_type_task_notification tn, 
 content_field_property_reference p, node n 
 WHERE  n.nid=p.field_property_reference_nid 
 AND tn.field_task_notice_type_value='Realtor Assignment' 
 AND  p.field_property_reference_nid='%d' ", $property-&gt;nid ));

 $task = @node_load( $task_id );

if($task &amp;&amp; $property-&gt;field_realtor_reference[0]['value'] == NULL)
   {
    $task-&gt;field_task_notice_status[0]['value'] = 'Pending';
    node_save($task);
   }
}
If you are careful you can use hook_node for this. You can check when node type property is saved, and load alter and save the task.

Make sure you put guards in place  otherwise it is easy to end up with recursion.