Using 2003

Goal was to use Conditional Format and/or a helper-column cell to isolate
duplicated records in a range.

The formulas used we
Conditional Format =IF(COUNTIF(Range1, B5)1,TRUE,FALSE)
(Cell turns Yellow)
Contigious cell =IF(COUNTIF(Range1,B2)1,"Duplicate","")


All of below cells do NOT have a duplicate thru 7 characters!
But XL senses duplicates via both above formulas!
M*D9000
M*D5000
M*D0004
M*D0035
M*D0002

Is there a "Bug" in XL that may see the second letter "*" as a wildcard OR
stops the compare at "M*" ? therefore evaluating all five as identical only
to the first two characters?

TIA Dennis
In both cases the formulas identified the following as duplicates: