Have deleted all calendar entries on Nokia E71?

I have accidentally deleted all calendar entries on my Nokia E71.

Is there an Undo?

Suspecting that there isn't I have the calendar entries within Microsoft Outlook, but I'm concerned that the next time I let the mobile and Outlook sync, all the entries will also be removed from Outlook. How can I sync having told the software to preserve what is within Outlook and override what is held on the mobile?

I am using a Nokia E71, Nokia PC Suite 7.1 and Outlook 2007.