I have 2 list of data

All student
-----------
John
Peter
Mary
Anne
Belle
Cindy
Doreen
Ellen
Gerry
Jane
Hazel
Lynn
Kelly
Sally
Tani
Ruby
Wendy....5000 students


Special Students
----------------
Belle
Jane
Hazel
Ruby.... 60 students


I need to compare All students against Special Students.
If matched, mark such students in 'All'list so that deletion can be done
manually. If possible, automatically.

Can someone help me. My guess is that I have to use LookUp function.

Thanks