Transferring Ratings from Windows

Hi,
So I'm new to Mac and Aperture. I have transferred a large number of images from Windows to Mac that were all rated in windows. I would like to preserve those ratings. Anyone know a way of doing this?

What I have found is that the Windows ratings are in the Image files, not as the standard MAC 'Ratings' but they are there as an IPTC Data field called 'StarRating'. So I can add this to the metadata view field and see those ratings. If I could Search on this field I could then search for these and bulk update them. However in the search field this 'StarRating' field does not show up as an searchable field anywhere.

Anyone know any solutions?

thanks
J