Hi Stefano
a few more details would have allowed us to give a more detailed answer but
the general syntax of a nested IF function is
=IF(test,IF(test,true,false),IF(test,true,false)
where there is an IF nested in both the true and the false sections of the
original IF. Note, you can only nest up to 7 levels. An alternative to the
IF function is the VLOOKUP function.
if you would like more assistance please provide additional details.