Macro to add new rows with information to add in existing sheet

Please help

Sheet 1 includes all the information of clients except the email address
Each record has a unique Client ID
Some records use 2 rows and some use more than 2 rows

Sheet2 includes only some clients who have now given their email
Column B of Sheet 2 includes client code
Column C of Sheet 2 includes Client Email Address,

There are about 10,000 clients.

Is there an easy way to

1) Add a new row for each client that looks up client code from Column B of
Sheet 2 and copy Email Address from Column C to The Newly added row in Sheet 1