the dr is going to want you to describe your pain. i'm recovering from a substantial injury to my leg and low back, so a big part of my life has been consumed by learning how to effectively describe pain.
you'll be asked to rate your pain on a 0-10 scale, where 0 is zero pain, and 10 is the worst pain you've ever felt. your best option here is honesty. in my opinion, doctors expect that you are embellishing your pain. for instance, if you say your pain level is at a 9, and you don't display corresponding physical symptoms like elevated heart rate, your 9 is going to be seen as not credible.
otoh, stoicism isn't rewarded. meaning, if you decide you're going to tough it out, and under rate your pain, you'll be doing yourself a disservice.
other aspects of how you describe your pain are important as well and basically boil down to helping determine if your pain is caused by nerve damage vs muscle/skeletal pain. typically nerve pain is felt as burning, sharp, electric whereas muscle/bone pain is achy, deep, constant.
the language of pain can become quite lyrical.
you'll probably be asked about your range of motion, what causes the pain, when is it the worst, other symptoms that you have. the doc will be trying to build as complete a picture as he can of what might be the root cause: vertebral fracture, bulging disc, compressed nerve, who knows.
i think its fairly unrealistic to expect that a doctor that you have no relationship with is going to give you more than vicoden after your first visit. back pain is a big deal. throwing opiates at it is just going to mask what's really wrong.
my advice would be to not ask for any drugs of any kind during the first visit. let the doctor prescribe what he thinks is best. for one, it will help you avoid being characterized as drug seeking (and lemme tell you, all it takes is one a-hole dr to put that in your record somewhere and life becomes much, much more difficult drug-wise), for two, you may not really need oxy.
bear in mind that more and more dr's are requiring UA's before they'll prescribe narcotics. for my oxy script i get UA'd every two weeks. if you're not comfortable passing the UA, and from many of your posts recently, i'd be willing to bet you aren't going to pass a UA clean, then you don't want to have that spectre haunting you right out of the gate.
i dunno. i've had a lot of experience with pain and trauma and pain relieving prescriptions over the past few months. best of luck. hope your back feels better.