Embed field data to Subject field.

Embed field data to Subject field.

Greetings,

I am trying to set up the follow:
  1. I have a contact record open.
  2. On the right hand column I click on "Send Mail". Mail form pops up.
  3. Most header fields are populated (except Subject:)
  4. I would like to capture and embed the "Account Number" into the beginning of subject line of the email form.
  5. NOTE: the are 2 fields "Acct ID" and "Account Number".

Example: SUBJECT:  ENG-1002 - 

Leaving the space after the dash for me to add to the subject title.

Hopefully this is possible....

Thanks in advance,
RMESA