Count rows down to previous occurrence

[imlearning]

Hello,
In this sample, I'm working with 2 sheets and I have inserted notes on what I am trying to do. Sheet1 has 5 columns of numbers and more will be added by inserting a row at row 1. Sheet2 has a set of 3 numbers and I would like a count of rows (in Sheet1) down to the previous occurrence of the set of 3 numbers. The 3 numbers can be in any of the 5 columns but need to be in the same row. The count should start at row 1 and count down but no more than 100 rows. If no occurrences, than I would like the count to be 0. Any help will be Greatly Appreciated! Thank U!