D Cornett wrote...
I suggest that you use an IF statement that includes your "," with your
criteria. . . .

As long as there wouldn't be space characters in any of the cells,
simpler to use something like

=SUBSTITUTE(TRIM(A1&" "&A2&" "&A3&" "&A4&" "&A5&" "&A6&" "&A7&" "
&A8&" "&A9&" "&A10&" "&A11&" "&A12&" "&A13&" "&A14&" "&A15&" "
&A16&" "&A17)," ",", ")