Code:
@ __CONFIG   _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
@ __CONFIG   _CONFIG1H, _FOSC_HSPLL_HS_1H
DEFINE OSC 48
Should work?

The external OSC does not matter to PBP here. The above should have the MCU running at 48MHz. That is what PBP cares about.