Hello Hidyath,
Like you also know, secondary cost element can only be directly posted to CO.
Anyway, I believe you have NewGL active in your system, therefore
the easiest way to have the postings work as they are, but also
post to FI is to activate the update in the FICO Real time integration
now that you have NewGL this is easier than without:
You can maintain the following that will take effect on future postings,
if you change the setting to 'all CO LIs' then you will update FI
for the internal allocations. If you only want changes made because
of a company code then you would select the company code in a variant.
More information can be found in IMG under the documentation.
Financial Accounting
Financial Accounting (New)
Financial Accounting Global Settings (New)
Ledgers
Real-Time Integration of Controlling with Financial Accounting
Hope it is useful.
Best regards,
Jason