Data Validation and Throw Exception using Groovy Grid Iterator

Summary:

Groovy DataForm data validation - raise exception and highlight cells which are causing this causing.

Content (required):

I have quite number of columns on the dataform close to 50+ columns, and some the them drive cashflow number and some other columns for calculating regulatory output and some reports. Now the problem is when users load data through form they forget to input some of the columns, and there by causing impact on cashflow numbers. There are 10 columns that are key driving different cashflow elements, i have written groovy rule to run before save and stop user from saving data if key columns are missing using throwVetoException, also tried through addValidationError, for some reason neither of them