Int 21 Fn B4  U - Novell Netware - "attachhandle"                          [N]

   AH = B4h
   DS:SI -> input buffer (see below)

Return: AX = handle or return code

Note:  this is an interface provided by NetWare to give DOS file access to
     NetWare files on non-DOS systems such as Macintosh, OS/2, and Unix

Format of input buffer:
Offset Size    Description
 00h   BYTE    "WorkFileServer"
 01h   BYTE    access code
 02h   DWORD   "OpenHandle"
 06h   WORD    "OpenHandleCount"
 08h   DWORD   "OpenFileSize"