This will change the cell format when the content is *not* in the list of
part numbers
(a named range, which does not need to be on the same sheet).

=ISERROR(MATCH(B5,LIST1,0))

Tim

"mustngsalie" wrote in message
...
I am trying to flag part numbers when they are entered in a certain column
by
making it bold red. These part numbers contain letters and numbers. We
have
an extensive list of these part numbers on another sheet that I would like
for the program to review each time a part number is entered. I cannot
use
conditional formatting on the tool bar because it only allows for 3
conditions. Any suggestions. I know almost nothing about macros.