Hi, how do I config ECIO on 16F777

Searched forums, all examples of ECIO are on 18s.

This a 16F777 with an external oscillator on OSC1, and now run out of pins.
I need to config ECIO to turn off OSC2 and use the pin as RA6.

Simple enough, but the 16F777 INC clock list does not have ECIO and I cannot decode the anagrams. It's 20MHZ, not an R/C and MCS/PBP does not like extrc_io or extclk.

_EXTRC_CLKOUT EQU H'3FFF'
_EXTRC_IO EQU H'3FFE'
_INTRC_CLKOUT EQU H'3FFD'
_INTRC_IO EQU H'3FFC'
_EXTCLK EQU H'3FEF'
_HS_OSC EQU H'3FEE'
_XT_OSC EQU H'3FED'
_LP_OSC EQU H'3FEC'

Thanks for your help.