interesting. The first star on day one is elementary to solve just with a basic very Excel sheet, but the second star is much more difficult as it involves cyclic aruthmetic (you can solve it by brute force but it rapidly quite computing intensive as each test requires decomposing 1016 integers into primes in order to test which position to look at (otherwise the search loops are unbounded): you need some knowledge of cyclic arithmetic to solve it with an efficient algorithm which is ensured to find a solution in a bounded and in fact quite small time.
Your current test code in Haskell uses the brute force approach to repeat searches in more and more repeated cycles, but even if you find a repeated frequency with N cycles of the list, you could still find a lower frequency located below in the input list. There's a more efficient solution by sorting the frequencies produced by the first cycle. But then you need to apply the algorithm to compute a lowest common multiplier and see if it's divisible by a position in the sorted list. Finally you have to aplky a second sort... Technically you can still do that within Excel by several operations involding copying computed values from one column to another (without their formula) and then apply a custom sort. over a group of columns. All this could as well be done in Lua of course (instead of Excel, you need Lua tables)