Haven't so far tried blackcurrant sbut gooseberries operate in the same way. In the autumn I cut off a shoot, dipped it into hormone rooting powder, and potted it up in compost, keeping it in a sheltered place outdoors during the winter. It has thrived and lots of new shoots are now appearing. But if you can't wait until autumn, why not try this with a few shoots now, keeping them in pots for a couple of years until the roots establish themselves. Am sure you'll probably be lucky, especially if you put a clear polythene bag over them to keep the atmosphere humid. You'll certainly save yourself some money generating plants in this way. Alternatively, if you've you got some clear ground, you could always try sticking a couple of shoots direct into the ground in late spring and keeping them watered. You might be lucky and find the take root.