VBA Cell Analysis

Hello,

I have a spreadsheet of about 5000 rows.

The sheet is an XML export from a system, I believe that there are some completely unique records with the same first name as other records but slightly possibly different other details (such as address) in other columns.

However there are too many rows to use a Vlookup with, i have tried this and its slows the application instance of excel down completely.

I am looking for a way to do something similar to the following in VB

IF the value in cell A is different to the cells both above and below it (a-1 row & a+1 row) highlight in red

AND

Start at row 1 and check if the value of the cell is unique if it is highlight in blue

Thanks for your help in advance

i woudl share teh attachement, but it is confidential