Interesting problem finding peak to peak values in a dataset

Hi,
I have a waveform which contains a series of five samples.
original.PNG
I need to get the max peak-to peak value from each of the samples.
original.PNG

So at the moment my idea is to filter the flat lines between each sample to break them up, then scan through each individually.
I' managed to filter the flat lines though a comparison:
C3=ABS(B4-B3) etc
then
=IF(AND(C3<0.01,C4<0.01),NA(),B3) etc
filtered.PNG

but I'm stuck as to how I can determine the peak to peak of what remains.

Any ideas guys?