How to determine cross platform type during file save?

Hello,
I am overriding OnSaveDocument in my MFC document class to strip out the carriage returns when saving my app's document to a UNIX file system but not when the user is saving a file to a Windows file system.

Is there a way to determine if the lpszPathName in OnSaveDocument(LPCTSTR lpszPathName) is a UNIX or Windows file system?

Note, I want to avoid hard coding server names and I want to avoid overriding the FileSave dialog and forcing the user to select Windows or UNIX.


Thanks.