pszExtLIBPATH (PSZ) - input
This buffer has a maximum size of 1024 bytes.
A pointer to a NULL string removes the extended LIBPATH.
flags (ULONG) - input
Possible values are described in the following list:
BEGIN_LIBPATH (1)
ulrc (APIRET) - returns
DosSetExtLIBPATH returns one of the following values: