Here's a commented version of what Gregory posted. I'm very OCD about documenting how things work and this is an example of the kind of basic help patchers I wish existed for Gen to help us mortals get our heads around simple patching operations like this in Gen.
When I see the word 'function' I'm led to believe different instances of the same object can receive different parameter values. Is there a way to have multiple copies of an identical gen subpatch, each of which receive different params from the parent gen patch? Or, does one edit each one to have different params internally?