Outlook attachment removal & duplicates

Hi all,
Just a couple of questions regarding MS Outlook: 1)I want to do a full system backup for a reformat, but have one account folder with several thousand e-mails + attachments and (for this folder only) I’d like to remove the the attachments to a separate folder and then delete the e-mails (only from this folder though).
Also I have a folder which I receive e-mails from a newsgroup, however, I have recently started receiving triplicate messages which is becoming a pain – is there a setting in Outlook which will remove/bar duplicate/triplicate message delivery?
Many Thanks all,
Craig Duncan.