Budget Transfer Comments Not Traceable in Backend Tables (Data/Setup)

Summary:

We allow users to enter free-text comments/justification while performing a Budget Transfer between control budget accounts (Manage Budgets / Budgetary Control workarea). We need to build a custom BIP report that audits these transfers, including the comment entered at the time of transfer, for reconciliation and audit purposes.
We have reviewed and queried the following tables, which capture the transfer amounts and balances, but do not appear to store the user-entered comment:

XCC_BALANCE_ACTIVITIES
XCC_CONTROL_BUDGETS
XCC_BUDGET_ACCOUNTS
XCC_DATA_SETS

Please suggest how can we get the comments in the report which are entered by the user while doing the adjustment to budget through spreadsheet.