Adding new rules to a resource-assign using TMSH

I have a resource assign that has many rules with expressions that assign SAML resources. What I want to know is when using TMSH can I 'add' another rule using a TMSH command rather than having to list all other rules everytime in that command. so only need to add the new entry and the others remain there?

 

modify apm policy agent resource-assign TEST-resources_assignment_act_full_resource_assign_1_ag rules { }

 

Thanks