I’d like to include transactions from a period prior to VAT registrations in a current VAT return.

Those transactions which are in QB, were not included in the 1st return because they are dated prior to VAT registration. I’d like to manually include them in a current return (as ‘exceptions’, of course) following guidance received from HMRC & my accountant.
To manually “adjust” the figures in the return using a calculator, seems like a backwards and messy way of doing things.