How do I write a macro to automatically process the subject heading of specific email addresses and paste these subjects into a text file?

Hi Experts,

How do I write a macro to automatically process the subject heading of specific email addresses and paste these subjects into a text file?

The macro has to initiate upon receiving emails, check to see if the email is from  a specific email address and if it is, read the subject of the email into a text file.

Thanks!