Recreate a Before Rollup calculation in Excel

[cognox]

Please see the attachment to get a better picture of the issue.

I am using a calculation as a measure which is set to Before Rollup in regular timing (in transformer). Result: 183,111 (Column C in attachment)
I have the same calculation as a measure set to After Rollup in regular timing. Result: 113,715 (Column D in attachment)
The results are different.
When I use the data to calculate the same formula in Excel, the result is the same as After Rollup. (Column E).

Is there a way to re-create functions of Before Rollup in Excel? I need to present and justify the difference for my clients. The difference is significant.