Hi Hank,

Your solution would have worked just as well as my one, though
I've ended up going with Jamie's suggestion. (In part because I'm
trying to avoid variants whenever possible given the approach taken in
VB.Net, but more importantly it will allow other (future) methods to
use the same collection object without the need for more validation
coding.)

Fine - they're both equally good alternatives. If implementing the
custom collection bit, you might like to modify the Add method, so it
accepts a single sheet, or an array of sheets, collection of sheets,
Excel Sheets collection etc. (as in my example code), to make it as easy
as possible for your users to get their existing data structures into
your custom collection.

Regards

Stephen Bullen
Microsoft MVP - Excel
www.BMSLtd.ie