Hi,
It's possible to do with a PIC and PBP but it's not an easy task and not a suitable beginners project to implement the current control within the PIC itself.

A much easier (but still not a beginners project IMO) is to use an exernal driver with integrated PWM current control (such as the L6207 though there are many alternatives) and then use the PIC to generated the apropriate phase- (digital) and current reference (analog) signals.

You'd then use the two CCP modules to generate the two current refernce signals (SIN/COS) and a couple of I/O's to drive the digital inputs of the driver chip.

As for generating the SIN/COS reference signals there's been more than a couple of threads on this forum regarding that specific task (though it usually involves a student who's final project is to build a three phase inverter or motor drive), if you search the forum I'm sure you'll find a couple of threads that might be of interest.

What size of motor are we talking about here? Is a little NEMA11 with a rated current of couple of hundred mA and a suitable voltage of <24V or is it a NEMA56 which will need a hundred volts or more and currents in 10A range?

/Henrik.