Note that CPLEX and CP Optimizer are two completely different products. AFAIK, a license key for one of them can not be used for the other. But I've never actually used either myself, so don't take my word for it.
Also, since you seem to be interested in using Minizinc for modelling, you can use other back-ends than the built in one for solving models.
For some more code examples, see also Håkan Kjellerstrands blog (http://www.hakank.org/constraint_programming_blog/) which, among other things, contains numerous solutions to the xkcd problem suing different systems.
I have tested out using gecode as a minizinc backend as I like the look of gint. I've been skimming hakank.org but it is a little advance for me at the moment.
Is there a way to get a minizinc model into cp optimizer?
I have no idea if it is possible to use Minizinc models with CP Optimizer, but I would guess not. It doesn't feel like a feature that would be of business interest to IBM to develop.
