Archving e-mail in DTPO

I am trying to create an “old e-mail” archive in DTPO. My idea is to put all messages in a certain date range into the DTPO archive and then delete them from my IMAP account.

I am still stuck at the first step: I thought I could use the filter in the “import e-mail” panel, but the filter is apparently ignored when I use “import all”. I certainly don’t want to go through my mailbox hierarchy by hand to import the filtered messages, so this is not an option.

I suspect I could write an AppleScript for this task, but I’d first like to check if someone has a simpler idea.

Thanks in advance,