Help on configurable calculations

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Hi all,

I'm not an expert on configurable calculations and need your help. I'm trying to copy the Opening Balance of 'Cash' on parent-level to a new statistical account. I got it running on entity-level but then had the issue with fx-revaluation each period, while I would like to keep the Opening Balance (=cash ending balance from last year) w/o revaluation on the statistical account.

Please see my code below. The idea of the code is that only in P1 and only for "Parent", the opening balance is copied to "stat_OpeningBalance2".

As a screenshot attached you see the settings of the account. So far I've never worked with data input on parent level, but I'm assume that should be the way it works?!