Invert all your bits and have the outputs SINK current instead of sourcing
it for the LEDs.  Then RA4 or other "open drain" outputs should behave the
same (as far as LEDs are concerned) as the other outputs.  "open drain" or
"open collector" means that there's a switching transisitor to ground, but
not one to VCC.  This allows an external pullup resistor to VCC to "pull up"
all the signals if they're all "high" (ie "disconnected"), but any one of
them can pull the line down ("wired OR" (inverted))

BillW