removing duplicate rows

What I need help with is:
I need to search column A for duplicate entries than if it finds one change the value in column C to "COM", and then remove the duplicate row.

Not sure if this is even possible but any help would be greatly appreciated.

Graeme

process that im looking for is:

a2 compare to all other items in Column "A"
if duplicate delete duplicate row
put "COM" in the "C2"
then repeat replacing A2 with A3 and C2 with C3... and so on...

thanks for any help that can be given.


Graeme

process that im looking for is:

A2 compare to all other items in Column "A"
if duplicate delete duplicate row
put "COM" in the "C2"
then repeat replacing A2 with A3 and C2 with C3... and so on...

thanks for any help that can be given.

Graeme