One of three things may happen.
1. The beer carbonates fine and you drink it two weeks later and wonder: why was I so worried?
2. The cork is blown from the bottle. No harm done.
3. The bottle explodes.
As far as I know there is a difference between wine bottles and champagne bottles. Wine isn't carbonated and therefore doesn't need a bottle that can withstand the same pressures that a beer or champagne bottle must withstand. If your cork doesn't blow, there is a chance that your bottle will. If I were you, I would tape the cork on with duct tape, put the bottle in several plastic bags, and see what happens. Let it be an experiment. You may get some good beer out of it.
Primary: Robust Porter from BCS.
Bottled/Kegged: Crappy Bock (my first brew!), IPA, Manny's Octoberfest, Paulaner Hefe-weizen clone (my first all-grain!), Ed's Honey Oatmeal Stout, Dos Equis clone, Pumpkin Spice Ale (my first ruined batch), American Red Ale, Angel Wings from BCS, Edworts Apfelwein, American Wheat from BCS,Terrapin Rye Pale Ale from CYBI, Munich Madness from BCS.