The baby PIC's use TRISIO in place of TRISA, TRISB etc... (it is in the PBP manual section 2.5.1 PICmicro MCU Specific Issues).

By the way, check the PIC's Datasheet too... you'll discover you can't have GPIO.3 as Output... it's an input ONLY pin.

So, setting GPIO 0, 1 and 2 as OUTPUT and 3,4 and 5 as INPUT (which is the other way around to your request) you execute...

TRISIO=%111000

Melanie