Michael,
How this might be accomplished varies quite significantly based on how the queue call back was programmed and other parameters of scripts in your call center.
The most concrete way would be to have your script write to a database when a callback is requested, and update that record when a rep is successfully connected via the Connect step. From there you could program a quick web interface or otherwise to provide you that information.
Regards,
Tanner Ezell
www.ctilogic.com
Tanner Ezell
www.ctilogic.com