Do you use Outlook Express? If So you should be able to just click on address book on the top. Then go to edit and click on import--there should be three choices on the drop down menu. The one that's most probably what he saved would be the one marked WAB. If so it should come in just like that. If not, wait for him to call you back and then share with me. I've had it happen to me a few times and so far I've been lucky and was able to get it back the easy way.
Good luck!