Highly flexible sheet selection for multi-sheet data consolidations

Should have been doing other things, but a colleage raised the question of flexibly controlling 3D (multi-sheet) data consolidations. He had found some information in a very old news letter (http://j-walk.com/ss/excel/eee/eee003.txt), but had better things to do than pursue the problem to a solution. So did I, but I couldn't resist.
The solution requires use of the Indirect function as part of an array, and I've posted an illustration on the 'Resources' page of my website for anyone who's interested. http://www.projfinmod.co.uk/fmresources.html
The method allows totals to be calculated for data items across a selected sub-set of data sheets, provided some simple naming conventions are observed. Could be useful for consolidations of multiple projects for corporate level evaluations etc.

Hope this is some use to somebody, so I haven't entirely wasted an afternoon!

Penny