PLAR line key functionality with 3PCC phones

With our current Polycom offerings, we have the ability to go off-hook on a registered line and have it automatically dial a specified ext/TN. We use this functionality for a shared call appearance/shared VM box scenario to have a registered line monitor a VM box status and immediately dial into that VM box by going offhook.So far with the 3PCC phones on a non-UCM system, I have been unable to identify a way to have this dual functionality.Even if the line key could have a registration as well as act as a speed dial, it would suffice in my situation.