php script to handle automated email reply from application.

Hello Experts,

Here's my scenario:

I have a php form which sends email to application which inturn replies back with an automated email.  This automated email will include a ticket number.

Now what I want to do is to have the ticket number picked up from the automated email and send another email with the ticket number as the subject line.

Please guide me how this can be achieved.

NOTE: The automated email will be sent to the person whose email address is specified in the php form. I am phpmailer to send email in my form.

Thanks