It would probably be easier for the user (or at least more universally compatible) for someone to port the NoHands app. It would turn the N810 into an HFP handsfree device, allowing dialing to the phone, as well as serving as a "headset". I haven't tried NoHands yet, but it looks like what the OP was asking for, to me.
As for PhoneLink, that only works on non-crippled phones, so people in my situation (Telus, or similarly evil companies) likely won't be able to use it that way.