Access VBA importing spreadsheet containing key values when user only enters email address

Hi
In my Access database am using vba to import a spreadsheet containing data for a table where one column contains text and the other contains integers that are foreign key values for another table called Contacts. I want a user that prepares the spreadsheet to use the contact email and then have the import pull in the integer key value for that email address rather than the address. How do I achieve this? Do I use a technique in the spreadsheet or rather do something on the Access side