Changing a transaction content in a custom action?

Hello-

This might be a simple question but I am unsure how to do the
following: Is it possible to change the content of
$self->TransactionObj->ContentObj->SetContent VALUE in Custom action
preparation code? I am trying to take an web based email generated by
Metadot an transform the email into an RT ticket that has custom fields,
subject, etc… by parsing the email’s contents. I am sure it’s been
done before. If anyone has examples I would love to see them.

Thanks!
Davin Flatten