I don't know what wine conditioner is, but there are ways of using additives/chemicals to do this. If you look at the sticky thread at the top of this forum, you'll get an introduction to that.
Another option is to let it ferment out completely (so it is very dry), then add a nonfermentable to sweeten to taste (like lactose or splenda), prime and bottle.
I use a third technique - an easy, low tech pasteurization:
1. after the fermentation has been going for a few days, check the hydrometer reading and take a taste test - I'm looking to bottle the cider when it is semi-dry (a little sweetness), around 1.010 sg
2. when its at the right gravity and sweetness/dry balance for me, I bottle it, using priming sugar so that it doesn't get any drier in the bottle
3. after a week, start checking bottles for when they are carbonated enough - when they are carbed sufficiently, you need to stop the fermentation soon, or else you will have bottle bombs
4. to stop the fermentation, I pasteurize the bottles by heating a large stockpot of water to around 190 F, taking it off the heat, put in some bottles (in my pot I can do 6 botttles at a time without crowding the bottles), let sit for 10 minutes, and retrieve the bottles from the hot water. I check the temp of the water and if its still good, add more bottles and repeat. If the temp has dropped too much, I return it to the heat and raise the temp before adding the next set of bottles.
For a case, I need to go through this process 4 times to do all 24 bottles, takes a little less than an hour.
If you have any questions about this method, don't hesitate to ask. I like it because it involves no additives and chemicals (I only use pectic enzyme before the fermentation) and its easy. Of course, it requires you to keep an eye on things both during the fermentation (to make sure you bottle at the right time) and during bottle conditioning (to make sure you don't get bottle bombs).
Cheers!
