body header situations

I have a list that allows multi-parts(styled/attachment), and I have a =

recipe to insert a body header:

     :0 fhw
     | cat - header.txt

It works fine for all plain text mails. However for mails with multi-parts =

the "inserted" header does not show in distributed mails. I understand it =

must be that the header was inserted in the "begining of body" but outside =

of "multipart" boundary marks thus gets dropped in subsequent processes =

(by MTA or email clients).

Any possible work around?

Zhiliang