keep n duplicates not just a single instance - how

I have a sheet of 20k rows comprising company name/address and contact name address on the same row. Each company has between 1 to 400 contacts (rows).

Each contact appears on a separate row and has a unique ID for the company it belongs to on that row as well as a unique ID for the contact.

What I need to do is append a flag field for each row with LOAD or NOLOAD depending on this rule:

For each new company (unique ID) count the rows downwards associated with that ID. When the 9th row in that group occurs place NOLOAD in a flag field and keep doing this until there are no more rows in that account group. Do the same for the next unique ID (new account) and so on.
So I am effectively keeping 9 'duplicates' (contacts actually) of the account ID field and flagging the rest for subsequent removal (NOLOAD) that I can do with a filter later.

Hope this is do-able and appreciate any help rendered! Using Excel 2010.

Cheers

DAve


****Thanks to NBVC for solving this - works a treat!***

It is a bit unclear if you want to start "flagging" at the 9th occurance or the 10th.

If you want to begin at the 9th, then assuming you are starting in A2, enter this in the "flag column" at row 2:

=IF(COUNTIF(A$2:A2,A2)>=9,"NoLoad","Load")

If you want to begin at the 10th, then

=IF(COUNTIF(A$2:A2,A2)>9,"NoLoad","Load")

copied down the list