Like most people mentioned above, the answer is yes, sort of. If you are regaining weight or doing something insane like binging on fast food for every meal, it's probably going to work.
But you'll have to figure out the variables of your body's metabolic rate and how it reacts to changes in the environment (increased or decreased calories / different food combinations, etc.) before you can get an exact answer.
That being said, I have seen it done in this time frame, more than 23lb actually, though I have never been able to do something like this because my body can't handle it.
Oh and a quick note in case you do go trying something crazy, 23 pounds of visceral fat is incredibly uncomfortable. You're looking for subcutaneous, so if you go about getting your Super Size Me on, expect to be in some amount of pain (visceral fat pushing organs around, liver pain, etc.) until your body adjusts.
Just plan it out, try it out, and if you have to revise your deadline, so be it. Better to be fat and healthy than a statistic on the news.
14 years