adding a contact to a conversation

Hello,

I am constantly having the same problem: I get an email addressed to a
distribution list and I want to add one or more contacts. Currently I
am pressing "reply all" add the new contacts and deleting the "[Re:]"
from the subject.

I am writing a "C#" addin that will do the above:
1. I know for to read the currently selected emails.
2. I know how to add a button to the toolbar.

my questions are the following:
1. is it possible to use the textboxs for the CC, BCC and To section? I
mean, having a new Section called "ADD" and being able to press on the
"ADD" on using "CTRL+K".
2. is there a way to clone the original message so that I will not need
to populate all the attributes.

Thanks,
Lior