Hi,
Hmmm...an XNK file is a shortcut to an Exchange folder. I don't believe it holds your actual data, but rather the information about the shortcut.
So, as long as the original folder remains, you can just recreate the shortcut to that folder again; but first, you'll have to make sure that Outlook 2007 has a connection to XNK files using the information from this article:
http://www.slipstick.com/problems/xn...not-open-file/