Create a function in the Admin Portal to mass update customer fields

In the current Site Manager Imports, the Customer Import is available, but there are a number of required columns that make it hard to do a quick update of customer data. It appears that the import performs a match by customer name, address, etc. in order for the update to happen. It would be much more efficient to have the system update based on one unique identifier field - and that's the only required column for udpating existing customers.