here's how I set up the registers to use HPWM:

PR2 = %00011001 ' Set PWM frequency to +/- 40kHz, set to 26 for 38kHz or 28 for 36kHz
CCP1CON = %00001100 ' Mode select = PWM
T2CON = %00000100 ' Timer2 ON + 1:1 prescale
CCPR1L = %00001101 ' PWM duty cycle 50%