IVRs and ringing back from GoogleVoice

First, let me apologize in advance if I’ve committed some violation of forum decorum (rhymes!) regarding placement of my thread or the manner of posing my support request – this is my first post, and I’m happy to oblige any suggestion to alter my post in order to comply with those conventions. That said…

Here’s my situation:

I have managed to set up PBX-in-a-flash, using free numbers from GoogleVoice and SipGate, configured to originate outbound calls from my PBXIAF box using my SipGate number, thru GoogleVoice to the number I want to reach. I know that might seem convoluted, so let me explain.

The way it works, simply, is that when I dial my target number, say 800-555-1212, it automatically dials GV (from my SipGate number), gives GV the target number, and then GV places calls to that number and rings me back simultaneously on my SipGate number. So basically, I place the call, and I immediately get a call-back on “line 2,” which is ringing the target number when I pick it up. You can essentially do this with any ordinary phone system – you dial GV, then dial your target number, hang up, and then GV calls you back with the target number ringing on the other end.

My question is this: is there any way to implement a nifty IVR so that callers-in can select a particular extension out of several to ring? (i.e. “For Larry, dial 1. For Curly, dial 2. For Moe, dial 3.”) As far as I can tell, I cannot, because with an outbound call, GV would ring back my SipGate number, and get presented with the IVR menu that regular inbound calls get, and not know what to do since it isn’t a person.

Are there any tricks which would help me get GV to dial back directly to the extension that originated the call, but still present the IVR and its options to regular inbound callers?

I’ve built this basically for fun and I’m running it in my house. I was just wondering if I could have individual extensions for my roommates and a cool little IVR receptionist to direct calls. I just don’t see how people could dial out and have GV ring them back on the extension from which they are dialing – essentially bypassing the IVR – while still presenting the IVR to ordinary inbound callers.

Thanks in advance for any answers, even if you can only tell me conclusively that what I’d like to do cannot be done.