Set in a Groovy script the Response of a SOAP test step

Hi all,
I need to set the response of a SOAP test step in a groovy script without running the SOAP step.
I receive the correct SOAP response in groovy on a jms topic as a message and I have it as a string and I would like to set the SOAP step response with that string.
How could I do it?
Thank you,
Emanuele Ricci