How do I intercept canned data validation messages

I've got an editable data grid bound to a table with unique constraints. If the user violates the constraint by editing or adding a row, the grid catches it and give the message:"Error when committing the row to the original data store" "Column 'code_text' is constrained to be unique. Do you want to correct the value." How do I intercept the canned message so I can put up an easier to read message? I'd love to add a handler for datarow.EndEdit, but there is none.