A quick reply, on which I might expand later. I haven't ever tried to find the specification for the box you describe, but what appears in there are "names". These date back at least to 123 v2/DOS and I think to v1a. In 123, they were named ranges, but Excel's concept of a name is far more powerful, although 99.lots% of people use them in the old 123 way because they don't understand the power. Hawley & Hawley, Excel Hacks, ISBN 9780596006259 (but I'm certain there's a later edition), dedicate an entire chapter to name hacks. I'm sure I've given other examples on this site, but I have demonstrated dynamic names in Re^3: Win32::Ole excel external data range, although you may need to read the thread to get the context.

Regards,

John Davies

Update: corrected 123 version