lpcwstr
is a reference-pass pointer to an Unicode string.
lpwstr
is a reference (in/out) pointer to an Unicode string.
These three types are Unicode only. You are unlikely to need these unless you know your application only needs to run on Windows XP/Vista/7, or if you are interfacing to some of the few 'W' functions that are available on Windows ME. In that case you need to pass the correct function name, something like
FooBarW
with the
W
suffix, to
fli:define-foreign-function
.