How to write off a bad expense

Regards,

The accountant said that one expense item cannot be include into balance.

He did the taxes without that expense amount.

The expense was done in multiple times in the year and it is already consolidate into the quickbooks.

How can I remove that expense amount from my profit and lost report and also not to show in the balance sheet?

I saw in multiple places here that we can do a journal to adjust the year balance. I did the Credit on the account but I don't know what account to use as debit. 

Please help