Im trying to create an algorithm that, upon entering Persons ID and date,
will notify me if the individual has been randomly selected to receive a
gift. Each person should have a 20% chance of being selected.

A2 Cell: Any number
B2 Cell: Any date
C2 Cell: =IF(A2,IF(B2,E2,""),"")
E2 Cell: =IF(F2<=0.2,"Yes","No")
F2 Cell: =RAND( )

Problem: The RAND function updates with each entry, modifying the previously
entered records. Is there a way to prevent this from happening?