;macro
macro virtual_copy {
      local ..n
      ..n=$-$$
      rept 4 i:0 \{ if i<..n
         load virtual_copy_buf\#i byte from $$+i
      end if \}
      end virtual
      rept 4 i:0 \{ if i<..n
         db virtual_copy_buf\#i
      end if \} }
;test (will display "..passes, 2 bytes")
virtual
     db 2 dup(0)
virtual_copy