msys : convert datadir to windows directory syntax

[Vincent Torri]

Hello,

a program that I am porting to windows is using a macro defined in a 
configure script by:

AC_DEFINE_DIR([PACKAGE_DATA_DIR], [datadir], [Shared Data Directory.])

With msys, it is defined as /usr/local/share. But I use that macro with 
fopen, which returns an error (file not found)

I would like it to be c:/***/***/local/share

Is it possible ?

thank you

Vincent Torri