Ubuntu :: Using "cat" Command Within Menu.lst [Grub4DOS]?

First of all, I'm far from beeing a Linux or any other OS expert, so excuse me if my questions are dumb

I use grub4Dos to boot on an USB stick and launch various windows tools/installers.

The problem here is that windows 7 and vista installers both use a 'BOOT' folder containing the boot config files. (dcb, boot.sdi and some other stuff).Of course I can't have 2 folders with the same name at the same place (here the root of my usb stick).

So here is what I d'like to do :

I saw ( here url )
that grub allows the use of the cat command, which should allow me to change the content of the files in the 'BOOT' folder before chainloading any install.

Unfortunately I can't find a way of doing so.

Here is what I tried :

Code:
title Install Windows 7
root (hd0,0)
cat (hd0,0)/WIN7/dcb > (hd0,0)/BOOT/dcb
cat (hd0,0)/WIN7/boot.sdi > (hd0,0)/BOOT/boot.sdi
chainloader (hd0,0)/bootmgr
when I boot on my usb stick and try to launch the entry 'Install Windows 7' the cat command fails to find the files.