if I understood your problem, you need to make some pins behave as a logic gate.

what you need: define what logic gates you want to implement (and, or, xor, xnor...) and a method to select what logic gate will be selected at a given moment, choose pins for input and pin for output

do you have instructions that work with bits, read the input pins (bits), put the corresponding output (bit)

seems straightforward... you can even chose more than one output pin, so using your inputs you cold represent different gates in different output pins...

hth

orlando