Check if Workbook fully loaded...

Hello,
In my Access database I am loading a very large Excel Workbook.
It takes about three minutes for the workbook to load, so even
though the xlapp and workbook reference are immediate, it
takes quite along time for the workbook to display. I
was wondering if there was something (maybe a property)
I can check to see if the workbook is fully loaded.
So far I've checked workbooks.count > 0 and xlApp.visible but
both are true right away, even though the workbok is not
fully loaded or visible. Thanks for any help.
Matt