landlord question please

Hi, My properties are managed by letting agents. I get a payment each month from which the the agent's fee has already been deducted. On my 'old' spreadsheets' system I would enter the total rental payment without the letting fee deducted in the 'income' column, and then explain the agent's fee as an expense on the other side. However, with the automatic bank feed payment amount already imported (which obviously is the rent minus the agent's fee) I can't find a way to correctly apportion the rental income and the agent's fee. Can anyone help please? Thank you