Hi John,
If I understand you correctly, what you are looking for is called Row Links. What this enables you to do is have multiple financial dimension links within one row format. You can add a link by clicking on Edit within the Row format and then I believe it's Row Linking (or something similar). You can name each link and you can have several. Each one will add a new column after the default row link within the row format. So this way you can have a standard row format but each row link can have different accounts listed per line on the report.
Then in your tree, you'd specify per tree unit which row link to use so each international unit would be using it's own row link on your row format. This will allow you to consolidate companies that have different COA's in them.
I believe there is a setting on the report that you want to make sure is checked. Something like "Use Row Definition from Reporting Tree".
Hopefully I was understanding what you are trying to do.