Ranking fields using VB Component

I am writing a search component to be hooked into an asp page. I want to return results sorted by their ranking based on three fields;

Primary Categorisation
Secondary Categorisation
Keywords

I want to look at each field and if the word exists then add 1 to a counter for each field. The values will then be written back to the recordset and used for sorting. An example is

PC SC KW
5 5 8
5 4 10
5 4 7
4 3 11
0 5 4
0 3 6
0 0 5
0 0 4
A word will only appear once in each field. Any suggestions as to the best way to do this?