Help: Excel 4 macro suddenly no longer working
 

I have Excel 2000 under Win 2000, running spreadsheets containing a
(big) Excel 4 macro in a separate sheet.
It has worked for 2 years now without a problem.

Suddenly, it does not work any more.
The macro stops and reports an error when it meets an instruction of
the following type: =SELECT("INDEX(recdat;1;1)")
("recdat" is a user-defined array , "SELECT" is tentatively translated
from French "SELECTIONNER"))

In other words, this instruction is no longer recognized by the Excel
macro interpreter.
I have done alls sorts of changes to my system lately, mostly
related to the Internet, but I have lost track of all these changes.

Is there someone who could guess what kind of change to my
Excel - or to my Windows 2000 - could have caused this problem?

Incidentally, I have another instance of Win 2000 with Excel 2000 on a
different partition of this machine, which I am not using often (and
not "updating"). There, it still runs fine.....

Thanks for any hint or suggestion

KS