mark partial duplicates

[mastertiger]

hello everyone

I have a huge sheet 16000 row its item master file

so in description of each item there is part number or unique value it always contained number
I wont formula for more than 4 number are same to mark this cell
as example

[TABLE="width: 540"]
<colgroup><col></colgroup><tbody>[TR]
[TD]Sensor, SMR6206 TS J, 1208
[TABLE="width: 540"]
<colgroup><col></colgroup><tbody>[TR]
[TD]Sensor, SMR6206 TS J, 1410[/TD]
[/TR]
</tbody>[/TABLE]
<strike></strike>
[/TD]
[/TR]
</tbody>[/TABLE]

 

[mastertiger]

any help please