I'd like to pass to a method an object, and a REFERENCE (handle?) to one of its properties, so it can refer to the value and operate on it. (For specific reasons, I CANNOT pass the actual value; it ...

I don't do this directly - get NUnit and NUnitForms. They can get the objects and handles (so you can click them, and type stuff) by object name. It should speed things up for you a little.