I've been hunting around for some time now, trying to find a list of
objects, methods, and properties available to a C3PO written in VB. I've
got the SDK, but I can't find anything in there that addresses things like
how to access fields (e.g. sender, recipient, subject, message body, etc)
of a message.

What I'm trying to do is to write a C3PO that will take a received
message, massage it a bit, and forward it on to another address, in an
attempt to provide "bounce" functionality in GW. Our new CEO uses a Treo
PDA to access his e-mail at our sister company (which runs Exchange), and
would like to have mail sent to his address here (where we run GW)
forwarded to Exchange so he can read/reply on his PDA. That's easy enough
to do, except that when you forward in a rule, it forwards as an
attachment, which makes it hard for him to access on his Treo.
"Delegate" works a little better, but messes up the headers so when he
replies from Exchange, he ends up replying to his own GW account rather
than the original sender.

Any suggestions?