Migration of historical balances

Hello to all

I have a question regarding the migration of historical balances from our old system to Netsuite

We are trying to import the historical balances, month by month for the year 2022.

We have a parent subsidiary and 4 sub subsidiaries

When we try to import the month of January ( for example ) as a journal entry, we have a problem on the intercompany part

Indeed in our historical balance of the month of January for a subsidiary, some accounts are flagged eliminate and therefore a name is mandatory.

We have therefore created dummy accounts in non-eliminate for the intercompany part to import everything.

However, we cannot create advanced intercompany journals because we do not always have a correspondence for each subsidiary (for example, the parent company issues a sales invoice for the daughter subsidiary, but we do not have a counterparty on the daughter side that enters a supplier invoice / and some other examples with cash account etc).

How to reclassify the dummy accounts to the right flagged intercompany accounts without Advance Intercompany JE

? Can we manually enter journal entries (dummy account to intercompany account) with the field eliminate and to subsidiarie?

How does the elimination work? What will be the elimination entries?

Thank you very much for your help