Edit: just saw your second post - let me look at that - cheers

Thanks for your help so far, much appreciated.
Unfortunately the size of the range of the data is variable (as is the start point). I have everything outomated (its periodic data) and the proposed solution would be quite difficult to integrate. Is it possible to do this in one cell, in a manner where the start and end of the range can be determined using indirect/offset?

I guess, Im looking for a "maxdeviation(range,k) solution or something that looks a little like it format wise. I'm beggining to fear this might not be achievable!
Did you have any further thoughts?