Yes, this is possible. From the System menu, choose Backup / Restore. Then under Select a Task drop down menu, choose Restore from Archives. If your full backup was to tape then ensure that the available archives device is selected as your tape drive. If it was to a network file, then ensure the network is selected. Then click on Retrieve Directory.
This may take awhile depending if you are retrieving this data from tape or over the network. Retrieving from tape ususally takes a long time (at least on my system).
Once the directories are retrieved, you should be able to find the date and time of the full backup and then just follow the screen prompts to drill down to the mailbox you want.