Hi Veronika,
I marked this thread to reply later, but just stumbling upon it now. I'm not sure if it will be helpful, or if you already designed another solution.
The functionality I mentioned earlier was a consolidated intercompany finance data.
This was done using some Code used for generating Trial Balance, and some additional Code, with some changeCompany's in the Code.
The Code prepared data for a temporary table, which was then displayed in the form. A Ctrl + T takes it to Excel.
The difference is, we developed some new Journal types to handle some Special Profit/loss postings, the amounts based from the Report generated above.
You can similarly post the Goodwill of your child Company as some Kind of Profit to the parent Company, and another to negate the same in the child Company.
In our case, the child Company had some significant Profit by another means, which the internal Auditor wanted to be removed/transferred to the parent at any cost. That's the reason for the new inter-Company consolidation.
I'd rather share my ideas here in the Forum (instead of private emails) so it could help a wider audience.