I have this working now. You are limited a bit by the adc input, but so long as any switch you implement is held above logic high say >4v and has enough impedance not to effect the serial data when it appears on the pin, then you can have an input on the adc so long as you stay within that top 1 volt. A few switches and carefully choosen pd resistors works.

Nice for 8 pin pics as I was short of an output pin for my lcd. Now I have serial output and adc input on the same pin