Hi,
Basically, Yes. HPWM provides 4 output (pin) signals, synchronised in Frequency and Duty Cycle (but differing in polarity and phase). You can use any one of those output pins as a "normal" PWM drive and ignore (i.e. not use) the remaining pins. Or it may be possible to configure the HPWM module to disable the unwanted signals (so that they can be used for another purpose), perhaps by direct command, or by a POKESFR, depending on the particular PICaxe chip.
Cheers, Alan.