Import CSV file comparing by First or Last Name

Hello,

I have an Excel file which has First Name, Last Name and otherPager which we are using for our badge reading devices attached to scanners.

I need to read the Excel file and then compare the name (either first or last but preferably last name) and then import (overwrite existing value) in the otherPager field from the value in the Excel file.

I am able to read the file but a bit confused on the comparison to validate the users from the file to the AD account.

Any help is appreciated.

Thanks,

Chris