Thank you both so much!

I appreciate it immensely! My aim is to use only the data between peaks 3 and 4. Following on from this, after obtaining 90.85 and 90.3, is there anyway to set these values as limits, and maybe use conditional formatting to highlight or even move the data which is between (and equal to) 90.85 and 90.3 (the two peaks and no other data throughout which satisfies this)?