You will need to first copy the files from the boot directories of each installation into the ubuntu boot directory (which is the boot directory used by your bootloader). I would setup a subfolder within that directory for each OS to keep the similar files seperated. You should be able to use the ubuntu lines from /boot/grub/menu.lst to extract the syntax necessary for each of the distros to tbe added to that file. Once the synatax and necessary files and added they should appear in the boot loader, I am sorry that I cannot help further at this point, but I do not know the kernels, vmlinux and initrd files used by each of your distros.