Maybe not the official answer, but I'd use the following workaround:
* Create a new folder, any name, just a temporary one
* Copy (not move) your messages into this folder
* Create a special forward template just for these messages using the from override: %FROM="%OFromName <%OFromAddr>". I would also add a key word into the subject line to make filtering easier - just some random characters that you know to look for.
* Set up a filter on your mailing list to detect messages where the reply-to address is your own and the subject contains your keyword
* select all the messages in the folder and hit forward, in the dialog box, select 'send all to this address' and insert your own address there, then hit OK

This will forward each of the messages back to your filtering system and allow it to re-add them to the database.  Once done, you can delete the temporary folder and all the messages (since they were copied).

Hope that helps!

Dave
another end user ^^