You can do this with Pivot and Preflow. We've done this in a lot of different ways, mostly using PHP scripts.
First, create the callflows you want to route the calls to, then check in Futon / CouchDB for the Callflow ID's. (however this might be possible to integrate directly into the PHP script instead of making different pre-defined callflows).
Then create a callflow with a Pivot request, pointing to the PHP script.
The PHP script then can route the call to the correct Callflow ID, it just has to return '{"module":"callflow","data":{"id":"<callflow_id>"}}'
To make the Pivot script run every time a call is being connected in you can select that as Preflow in the Callflow app -> Account Settings -> Misc -> Preflow.
Example Pivot callflow below:
Example PHP script:
<?php
header("content-type: application/json");
$nextcallflow="0219483204983";
die ('{"module":"callflow","data":{"id":"'.$nextcallflow.'"}}');
