I'm not sure that the Button Command "only works on PortB". Every other command works on any pin except the hardware modules (HPWM, HSERIN, etc).

Besides you can always use:

If btnTest = 0 then Blink 'did I change the button name? oops

Of course there is no debounce, but this is good for testing. Actually, your 1sec delay for the LED is a great debounce! nothing else is going to happen during that interval, nothing. You could also do this to BLINK as long as you hold the button down:

Start:

WHILE btnTest = 0
LED1 = 1
Pause 500
LED1 = 0
Pause 250
WEND

GOTO Start