Job Receipt to Inventory at MES - Lot Numbering

We would like to have our machine operators do the job receipt to inventory at the time they are reporting quantity. With the checking of Auto Receive at the final operation I am able to complete this. However, we need the lot number to be a sequential number that never repeats. When we currently do a job receipt to inventory we have the sequential lot number pulling from Part->Lots->Generate.

Is there anyway to make this same lot number pull at the report quantity/end activity screen on the MES? How do you make the lot number field on the MES report quantity screen accessible and not grayed out?