INT 21 - Windows95 - LONG FILENAME - GET SHORT (8.3) FILENAME FOR FILE
	AX = 7160h
	CL = 01h
	CH = SUBST expansion flag
	    00h return a path containing true path for a SUBSTed drive letter
	    80h return a path containing the SUBSTed drive letter
	DS:SI -> ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. long filename or path
	ES:DI -> 67-byte (possibly 128-byte) buffer for short filename
Return: CF set on error
	    AX = error code
		02h invalid component in directory path or drive letter only
		03h malformed path or invalid drive letter
	    ES:DI buffer unchanged
	CF clear if successful
	    ES:DI buffer filled with equivalent short filename (full path,
		  even if relative path given, and all uppercase)
Note:	this call returns the short name for any long-filename portions of
	  the provided pathname or filename
SeeAlso: AH=60h,AX=7160h/CL=00h,AX=7160h/CL=02h