Ok, kilroyscarnival, thank for your suggestions. I also thought tha such problem could only be solved with the use of an high level language, the availability and knowledge of which I do not have! Therefore, for the time being, I have to abandon the idea to solve this problem with a single excel formula! Of course personally I will continue to deepen my excel expertise so to try to implement you suggestions, but in this case we both surely agree that an end user can peacefully be called to simply use an excel procedure but not to make a maintenance of it!
So that’s, then, the end of it! Having nevertheless greatly appreciated your availability I duly wish to thank you and thank you very much for everything. A.P.