Jan... if the stone is located fairly deep inside one of the poles, your urologist is correct in his assessment in that it's unlikely that it will pass spontaneously.
However, I would ask your urologist if you're a a candidate for ESWL (Extracorporeal Shock Wave Lithotripsy). Just as the name implies, it's a shock-wave that they focus on the stone that breaks it up into smaller chuncks that are easier to pass individually.
I don't blame you for not wanting to go the 'perc' route (PCNL: Percutaneous Nephrolithotripsy). I've had several stone removals via PCNL and the recovery period, although not long, was very uncomfortable and not altogether pleasant.
As for managing your pain, unfortunately, all I can tell you is to drink PLENTY of fluids and stock up on narcotic pain-killers. Stay away from Vicodin (as the acetaminophen content is high and poses liver problems if used long-term). Norco (10/325) works well for managing pain of this nature (it's worked well for me), but if your pain-level is beyond that of Norco, you can go the morphine route with MS-Contin. Talk to your urologist about putting you in touch with a pain-management specialist. Most urologists won't prescribe (hesitate, as it's not their field of expertise) narcotics much beyond Norco, so you may need to see a pain-doc in order to get relief for your pain.
I had a 17mm stone that was not a candidate for ESWL (the type of stones I make do not break up when hit with shock-waves), and had to be removed via PCNL. My urologist managed to get it out in a one piece, and I have it sitting on my desk as I type this. If you end up having to have it removed via PCNL, ask them if you can keep it, for your troubles. Unless they really want it for pathology, they shouldn't have a problem giving it to you.
Good luck, and let us know how everything turns out.
Jan where is this stone in your kidney?