Easy! Just get a ponytail extension for the night. Way easier than permanent extensions (no glue bonding), a ponytail extension is simply a wig that you clip into your own hair. It all smoothes in together quite seamlessly and you can style the front of your hair any way you like. The long pony looks particularly good with a fringe, if you've got one, but if you don't a side part like Jessica Alba here is ultra glamorous.
Now who cares what you're wearing? You look all shiny and new anyway!