INT 21 - LANtastic v3+ - GET ACCOUNT
AX = 5F87h
DS:SI -> 128-byte buffer for account information (see below)
ES:DI -> ASCIZ machine name in form "\\machine"
Return: CF clear if successful
CF set on error
AX = error code
BX destroyed
Note:   must be logged into the specified machine

Format of user account structure:
Offset  Size    Description
00h 16 BYTEs   blank-padded username (zero-padded for v4.x)
10h 16 BYTEs   reserved (00h)
20h 32 BYTEs   user description
40h    BYTE    privilege bits
bit 7: bypass access control lists
6: bypass queue protection
5: treat as local process
4: bypass mail protection
3: allow audit entry creation
2: system manager
0: user cannot change password
41h    BYTE    maximum concurrent users
42h 42 BYTEs   bit map for disallowed half hours, beginning on Sunday
(bit set if half-hour not an allowed time)
6Ch    WORD    internal (0002h)
6Eh  2 WORDs   last login time
72h  2 WORDs   account expiration date (MSDOS-format year/month:day)
76h  2 WORDs   password expiration date (0 = none)
7Ah    BYTE    number of days to extend password after change (1-31)
00h if no extension required
7Bh  5 BYTEs   reserved
7Bh    BYTE    storage for first letter of user name when deleted (first
character is changed to 00h when deleting account)
7Ch    BYTE    extended privileges
7Dh  3 BYTEs   reserved

215F87 - LANtastic v3+ - GET ACCOUNT