somSelf (WPFileSystem *) - input
Points to an object of class WPFileSystem.
pszFilename (PSZ) - output
This buffer must be at least CCHMAXPATH characters in length.
fQualified (BOOL) - input
Possible values are as follows:
TRUE
pszBuf (PSZ) - returns
If the file exist, pszFilename is returned. If the file does not exist, NULL is returned.