How to use:
LABEL recoveryconsole COM32 chain.c32 APPEND cmldr=/cmldror:
LABEL recoveryconsole COM32 chain.c32 APPEND cmldr=/SETUPLDR.BIN
This will do the same as this Grub4Dos entry:
title find and load CMLDR, the Recovery Console of Windows NT/2K/XP chainloader /cmldr # write string "cmdcons" to memory 0000:7C03 in 2 steps: # step 1. Write 4 chars "cmdc" at 0000:7C03 write 0x7C03 0x63646D63 # step 2. Write 3 chars "ons" and an ending null at 0000:7C07 write 0x7C07 0x00736E6F
In the attachment you can find a compiled chain.c32 and the source code of the module. Get syslinux-3.84 for the other binaries (syslinux.exe, isolinux.bin and other modules) and source files.
With a bit of luck. This chain.c32 will be included in syslinux-3.85-pre1.