WS security header processing sequence

I am trying to use SOAPUI against an external webservice. The external webservice replies with a signed and encrypted message, the sequence is first signing and then encryption. I have configured MY SOAPUI for signing and encryption of the incoming message. However SOAPUI tries to first verify the signature instead of decrypting, hence it throws an error saying the signature "ID" cannot be found, which is very natural as the ID is encrypted and to get it, first decryption should be done. Is it possible to define the sequence of processing in SOAPUI?