Just a little addition to Dman's reply. Now, I don't have a set of promedia's yet, but the way I understand it, the stereo jack that you plug into the soundcard broke off. If it is the plug that connects to the wire from the preamp, then you have two choices:
1) If you need more wire, splice it, but make sure that you maintain the same polarity with the jack.
2) Just buy a new jack from radio shack, figure out which wire goes to which part of the jack, and then cut the old jack off and replace it with the new one, maintaining the same polarity.
Polarity shouldn't be that big of an issue, because I doubt that the promedia's have an extensive crossover network with phase-shifting and what not, but reversing the polarity will result in a 180 degree phase-shift.
Anyway, hope this helps.
-snap-