DX Deletion Question

I have a new EmailXtender and DiskXtender installed. DX is using virtual media on a Centera. At the beginning of the project, I began an archive task in EmailXtract to archive all email from 4 years to present. EmailXtender will then create container files for a certain months worth of archived messages. I anticipate the archive process to continue for a few more days.

There will be a retention initiative for 4 years worth of archived messages. Anything older then 4 years will then be deleted from Exchange, from EmailXtender, and from DiskXtender.

Question: How do you create automatic delete rules for all of these new files.

For example
-----------------
1. Today I archive email for 4 years to present
2. EmailXtender will create EMX files (container files) for these messages
3. The creation date for the EMX files will be today's date
4. I will have folders such as 200402, 200403, 200405 ... 200801, 200802 (a total of 48 folders with EMX files under...but all will have creation date of today
5. If I set a delete rule to delete files after 1461 days (4 years of retention), then ALL of these files will not be deleted until 201102


That being said, is there a better method for this? Meaning, when it becomes March 2008 (tomorrow), I want DX to delete all files from 200402 since this falls after 4 years, but the creation date of the files is actually February 2008.

Thanks for all your help and advice.