Superprisingly, it worked. I must have experimented with a least 5 litres (in 500 ml batches) of supermarket babymilk, all of which failed. But the real stuff worked. I'll post some pictures tomorrow, but basicly I add LOTS of CaCl2 and rennet as well as enough powdered milk to raise the proteincontent to about 5%. Then I waited 2 hours for it to coagulate, break was moderate to OK, I cut it and heated it up to 45 degrees celcius before touching the curd. This firmed it up enough so that I could slowly mix it. Curds were good and quite firm.
one well, minor, problem: the milk seems to have gone bad in the freezer.
The smell is quite unappatizing, not soury, but definately off. So as an experiment it seems to have worked, but not as an actual edible product.