Int 2F Fn AE01  U - Dos 3.3+ Internal - Installable Command - Execute      [l]

   AX = AE01h
   DX = magic value FFFFh
   CH = 00h
   CL = length of command name (4DOS v4.0)
   DS:BX -> command line buffer (see #2661)
   DS:SI -> command name buffer (see #2662)

Return: DS:SI buffer updated
     if length byte is nonzero, the following bytes contain the uppercase
     internal command to execute and the command line buffer contains the
     command's parameters (the first DS:[SI] bytes are ignored)

Notes: this call requests execution of the command which a previous call to
     AX=AE00h indicated was resident
   APPEND hooks this call
BUG:   Novell DOS 7.0's COMMAND.COM (prior to Update 12) will attempt to run
     a disk program with the indicated name even if the returned length
     byte is zero, because the register used to flag this case is
     clobbered without first checking it.  The workaround is to set the
     command name buffer to "REM" followed by enough blanks to pad out
     the original command's length, which will also work with MS-DOS 6.
     (from padgett@tccslr.dnet.mmc.com)

See Also: AX=AE00h