[Wine] Get OS version information within a batch script

[bitfail]

How would one find out if a batch script was running on wine versus some version of win32 natively? I want to be able to remind the user that a native Linux port is available for various distros, but only if the install script realizes it is running on a Linux machine.

I searched online and found some stuff that can find versions of win32, but not wine as well. On of the ones that look promising were: http://malektips.com/xp_dos_0025p.html but I might be wrong.
 
Thanks