It turns out PIC BASIC calls this isolating bits, not masking. I found instructions for that on p.37 of my manual:

B0 = B0 & %00000001 ' Isolate bit 0 of B0

This brings up another question, is it possible to concatenate bits? Like this:

A0 = (B0 & %00000111) SomeBitCommand (C0 & %11111000)

Robert