Are you going to use EntLib's trace listener to log to the database and to the event viewer?
I'm not sure what you meant by "eventlog format"; EntLib's Logging Application Block uses a LogEntry object and is able to log its contents to a database and event viewer.
Anyway, looking at EntLib's source code, specifically in the Logging.MsmqDistributor's MsmqLogDistributor will help. Or you can google how to read message from message queue.
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