When I used Spamcop, I had the following applescript for PowerMail (not sure which version). I ran it, and then pasted into an email addressed to the spam reporting address:
tell application "PowerMail"
set theMessages to current messages
if (count of theMessages) > 1 then
error -128
end if
set theMessage to item 1 of theMessages
set theSource to source of theMessage
end tell
set the clipboard to theSource

