I had a situation not all that different from yours. They wanted to know how many outbound contacts an agent had made via the dialer.
Yes, Symposium is an inbound solution, so I simply made it look like it was an inbound call.
The dialer looks at agents logged into an ACD a places calls based on various factors like # of Agents, avg. talk time, etc. The dialer then knows that it needs to dial so many calls (with an expected failure rate) to get a live person on the other end to send to an agent.
I simply fooled my dialer into sending the call to a Symposium controled CDN rather than straight to the ACD. At the CDN, I then skillset route the call to an agent in the dialer's ACD. This way the call looks like it was generated and delivered by the dialer, to the dialer. Yet, it looks like an inbound call routed to an agent to the Symposium. The agent's stats only show contacts that were generated by the dialer.