Test it. Use of XLM functions in defined names will crash Excel 97 and
2000 (and probably also Excel 95).

I have. Been using XLM functions in defined names for a few years under XL97
and 2K and have never run into problems. But, as you could see, I have
mentioned your comment in my post.

If the OP's really in a school environment, then the odds are high (at
least in the US) that there's more than one version of each application in
use.

Maybe - you know better, I am not in the US :-) That's why I thought
appropriate to quote you in my post.

That said, it's difficult to see why such functionality would be needed in
worksheets that aren't static in design, i.e., referring to worksheets by
index number doesn't make sense in spreadsheet apps in which users could
insert or delete arbitrary worksheets (and thus fubar worksheet
references). If workbooks would be static/unchanging in terms of worksheet
number and order, it'd be safer to enter a list of worksheets in a range
in one of the worksheets (or use a new worksheet just to hold such a
list), name that range SheetArray (tangent: always better to use mixed
case for defined names and UDFs to make it immediately obvious they differ
from built-in functions), and use it instead.

agree.

KL