How to lookup two names in a non standard text string and return value in the next column

I have a membership table in Excel 2007. The members payments are downloaded from the bank every month and I want to be able to populate the monthly payments into the membership table. The main problem I am having is that the text string containing the names varies for each entry and some surnames are duplicated.

I need a formula that can look up both the first name and the surname and return the membership amount into the table.

I have attached a spreadsheet showing what I want to achieve (all names have been changed).

What is the best way for me to do this?

All ideas gratefully received

Thank you

Helen