I'm a bit confused why do you want to do that so strange way?

To install Nemo from a rootfs image is pretty straightforward.

Now, first thing is to repartition your mmcblk0 using the MOSLO boot kernel. To do that you need just to boot the kernel with flasher like it says on the wiki page. I assume you have done this already, and have the ALT_OS partition on your device or else you should not proceed!.

Then, you need to unpack the rootfs bz2 file. For that I guess you can use 7-zip or whatever people use on Windows.

After that, there's no need for any "W32DiskImager.exe" things, I have not even heard of such, whatever it is supposed to do?
Just copy the unpacked file (which now has a .tar extension) to your MyDocs and do the unpacking on the device:
1. Open console
2. devel-su
3. mount /dev/mmcblk0p4 /mnt
4. tar -xvf your_archive_path_and_name.tar -C /mnt/
5. sync
6. umount /mnt

There, youre done