Hi Lesley ,
Your formula is quite a long one , and involves calculation of 2 MATCH functions and 1 INDEX function.
Assuming that this formula is designated as Your Formula , if you want to add an IF statement to check for whether the return value of this formula is 0 , then it will become :
=IF(Your Formula = 0 , Your Message , Your Formula)
which is a waste of calculations.
Khalid's suggestion to just use a custom format to display a custom message in a cell if it contains 0 will avoid this multiple calculation.
Narayan