forwarding from virtual email account to real email account

Hi All, Is it possible that we create a virtual email account(no physical existence) e.g abc@example.com which will be associated with a real email account e.g. real@yahoo.com so that if any body sends the email to virtual email account abc@example.com will be automatically forwarded to the real email account real@yahoo.com. Is it achievable using PHP ? Please throw some light as this becoming a major requirement of my client. Thanks in adance, Binay