Recording cell value changes from DDE triggered interface

[tom412]

at 9:00 cell A1 value = 0
at 9:05 cell A1 value = 5 (max before reverting back to 0)
at 9:10 cell A1 value = 0
at 9:15 cell A1 value = 15 (max before reverting back to 0)
at 9:20 cell A1 value = 0

Need to 'record', assuming with VBA code, the maximum values for A1 in between reversion's back to 0. Preference for display of info ... in a series of columns down the page as many time as the values changes ...
0
5
0
15
0

Thanks very very much in advance should you be able to offer assistance ....