Writeback for comments on existing Qlik table

Hi - has anyone out there used the writeback table to record comments against an existing Qlik Table.

I need the user to only see the latest comment in the writeback table but to keep a log of the history in the background to allow them to look back over their comments.

Eg I'm using it for a list of customers with their current balance (debtors).  I can either use the update which only show one comment in the table per customer but doesn't retain the history, or use insert, which then keeps the history but shows a line on the writeback table for each comment added.

Many thanks

Ade