Use a backup software program like PIM BackUp, SPB Backup, or Sprite Backup.
These programs will all let you store the backed up messages to your storage card
on your device. The file it creates after the back up, can then be moved to your computer.
Here are the links to backup programs I mentioned.
PIM Backup(freeware)-
http://freewareppc.com/database/pimbackup.shtml
SPB BackUp(pay program/free trial available)-
http://www.spbsoftwarehouse.com/products/backup/?en
Sprite BackUp(pay program/free trial available)-
http://www.spritesoftware.com/produc...p/full-edition
Hope this helps ya out, and if it did, don't forget to hit the green "Thanks" button in the lower right corner
-Keir-