> > Has anyone used this pin to control voltages above VDD ?

In my WISP programmer I use RA4 to switch the VSS of the 16x84 which is
being programmed.
Works fine.
When in high impedance the voltage on RA4 is ~14V, so their is clearly no
protection diode to
either VDD or VSS (both at ~5V).
Someone on the PICLIST (I don't remember who) said that this was allowed.
For details: www.xs4all.nl/~wf/wouter/pic/wisp
regrads,
Wouter.