Ron Rosenfeld wrote...
....
Download and install Longre's free morefunc.xll add-in from
http://xcell05.free.fr/

Agreed.

Then use this array-formula. To enter an array formula, hold down
<ctrl<shift while hitting <enter. Excel will place braces {...} around the
formula:

=COUNTDIFF(REGEX.MID(A1,"[^,]+",ROW(
INDIRECT("$1:"&REGEX.COUNT(A1,"[^,]+")))))
....

Avoid volatile functions. One possibility would be using MOREFUNC's
INTVECTOR function rather than ROW(INDIRECT(...)), but for short
strings, I'd just use

=COUNTDIFF(EVAL("{"""&SUBSTITUTE(A2,",",""",""")&" ""}"))