HMR to update p-asserted-identity

Hello,

 

I was hoping I would be able to obtain some assistance with creating an HMR that will modify the p-asserted-identity from a specific inside realm.  Currently, our phone system sends outbound calls with a p-asserted-identity as 

 

sip:1234567890@11.222.33.44:5060

 

I would like to create an HMR that takes any call from that specific inside realm and changes the p-asserted-identity to:

 

sip:1234567890@77.888.99.00:5060

 

Unfortunately, I do not have a development environment to try and test my attempt at HMR without fear of adversely affecting production traffic.  My attempt is below, would somebody be able to look at it an offer any suggestions on whether or not this is correct?  Thank you in advance.