(Excel equation) Find last non-zero value in a column. Apply it in the same column. Keep applying it when there's a zero in another column.

[MASGaming]

Tried for the D column:

#=IF(E5 <= 0, LOOKUP(2,1/($D$4:$D$33<>0),$D$4:$D$33), E5)#

I got this answer from this website but I'm unable to make it work properly. The sum in I4 doesn't calculate properly, either.

More details of issue in image:

Thanks for all your help!

 

[Aladin Akyurek]

You still did not tell where 5000 is coming from. If column E must contain a formula as well allow for a user entry, the task is not doable as such because these two ways cannot exist together within a range where the formula must be copied down.