Add a column to QuickBooks to a Homeowners Association Invoice

The Profit & Loss Detail Report has 9 columns. 7 are descriptive, the las two are Amount and Balance. I would like to add a third and fourth: Interest and Legal Expenses. So the last 4 columns would be Amount + Interest + Legal Exp = Total Amount, Balance (equals Total Amount + previous months Balance). Looking for someone in the Tallahassee, FL area.