Sorry my last post wasn't very clear.
This is the present set up -
In my Donors table the 2nd column contains the same information as is in the 2nd column of my Bank table. And so the coding that you provided me with made that link and allocated the money received from each donor in accordance with their percentages for each of a number of projects.

What I am trying to do -
1. In the Donors file the 4th, 5th & 7th columns contain the Name, Surname & Postcode for the donors.
2. In the other file (let's call it 'Tax') the same information is in the 2nd, 3rd & 5th columns.
3. The combined information in all 3 fields must be unique - there can be donors with the same Name & Surname but with different Postcodes so that is why I need to check all 3 fields for my latest project.

So my question is - can the VB code provided a year or so ago (which is working perfectly) be easily adapted to check the 3 fields instead of just one?
And I assume that if I use the same file (say 'Tax') as the 'Ledger' I will be able to get the result of applying the percentages from the Donors file to be added to the tax file.
I trust this helps to clarify what I am trying to do now.