How to deal with the second security header block with WSE2?

[Bo Yan]

My scenario is that one client need make soap request and send some
information to a soap server1, signed by its X509 cert.
Inside of the request information, part of it is encrypted by the X509 cert
of soap server2. SOAP server1 is not allowed to see this encrypted data,
however, server1 need make a soap request and send the encrypted data to soap
server2.
At the client side, using RequestSoapContext.ExtendedSecurity (API in WSE2),
I can create the second security header block to encrypt the information to
be sent to soap server2. When the message arrives at the soap
server1(ASP.Net1.1 and WSE2), I can use RequestSoapContext.Current.Envelope
to get that security header block.
My first question is: how to make server1 copy the second security header
block to the soap request to server2?
My 2nd question is: When the server2 receives the soap request containing
the 2 security header blocks, one from the original client and one from
server1, how to have server2 process those 2 security header blocks both for
the same recipient?

Thank you very much!
Bo Yan