Since QueueMetrics 1.4.6, you can now use an external script to act as an auth source for QueueMetrics. This can work in a number of ways, as described in the revised version of the "Accessing QueueMetrics through the XML-RPC interface".
We currently revised and updated it, so you can find it at
http://queuemetrics.com/download/QueueMetrics_XmlRpc_v16.pdfYour comments are welcome.