Munging Subject field

Hi All,
 
      I'm trying to prepend a tiny list-specific identifier to 
the Subject field.  IE, 'Subject: testing' would become
'Subject: test-list: testing'.  Haven't had much luck so far, using
the examples on extracting variables from headers.  Specifically,
the following does not work.

...down around the main header munger in rc.submit....

  :0 c
    SUBMIT='formail -xSubmit:'
    :0 wfh
      |formail    ....blah...blah...
        -i"Subject: $SUBMIT"
          ....etc.....

    Have tried variations of the -i switch (aAI etc), as well as pipe
symbol on the SUBMIT line, all either bomb, or simply return the
'formail..' string as the variable, rather than actually executing it.

thanks,
bob

P.S.  Solution will also have to look for prepended field in replies, and
not continue adding field if it's already been done in a previous post.

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rvanzant(_at_)van(_dot_)inc(_dot_)net               home of glass-panel mail 
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