extend subject with sieve - script possible?

[Patrick Näf]

Hello

Is it possible to manipulate the subject - header with a sieve script?
I have a script like this:
if header :contains :comparator "i;octet" "X-Spam-Status"
   "Yes" {
      ????
   }

Now I want to extend the subject, if there is spam in the mail.

Thank you for your help

Patrick