title: Excel - VBA/Formula for checking duplicate (similar*) records using multiple conditions
body: <p>I'm looking for some help with this one. I need to check an Excel file with approx. 40000 records for similar records, according to multiple conditions. I also need this to be fairly foolproof for someone not entirely IT savvy to do regularly once shown how. Therefore, a macro or formula based solution would be preferred.</p>
  
  <p>It seems easy enough to start with. Data has a header row with one record per row. It's easy enough to use conditional formatting to highlight rows with duplicate data in one or more columns, but I have an added complication. </p>
  
  <p>Problem: I need to find records which have the same data in columns E and F (Surname and DOB), and I need the record to be highlighted as a duplicate if the dates in column K are similar (i.e. within 10 days of each other). Only if all 3 conditions are met would the record be highlighted as a potential duplicate.</p>
  
  <p>Is this possible? I'm open to suggestions. </p>