[syslinux] retrieve a parameter in DOS

[mister.os2]

hi,

i was wondering how in DOS i can retrieve an additional parameter from 
within my dos batchfiles and/or scripts

a sample: an ascii file in my pxelinux.cfg contains following

   default memdisk
   append initrd=dos.img pwsname=abc123

when i boot this by pxe, i see:

command line: initrd=dos.img pwsname=abc123 BOOT_IMAGE=memdisk

question is: how can retrieve this parameter?