Does anyone know if there is a way to change the ELGC code on multiple F4812 records?

We have some large contracts that were to be invoiced as T&M
and now we want to change them to ELGC=4, cost only. I know there is a
Re-extend UBE but I can’t find a Row exit or UBE that will allow multiple records to be modified
without having to change each one. I know I can 'select multiple' but only want
to enter the change once, similar to changing the HOLD status. Thanks!