INT 21 U - DR DOS 5.0-6.0 internal - SET EXTENDED FILE ATTRIBUTES               
	AX = 4305h
	DS:DX -> 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. filename
	???
Return: CF clear if successful
	CF set on error
	    AX = error code (see #01680 at AH=59h/BX=0000h)
Desc:	this function allows the extended attributes, and optionally the
	  encrypted password, of a file to be set.
Note:	this function is only supported by DR DOS 5.0 and 6.0 and DRMDOS 5.1
SeeAlso: AX=4304h,AX=4311h