You can find Knoppix here
http://www.knoppix.org .
Simply burn it on a cd as an image file and boot from it.
If you've started a terminal in Knoppix, run 'cfdisk' (be careful not to accidentily change anything in that program) to see on which device you have installed linux.
Then run the grub-install command and replace the 'hda1' (which I used in my previous posts) with the device listed in cfdisk.
What do you mean with 'I can get Windows manually started?'
If you mean you have some sort of command-line in which you can enter the boot command for Windows, than you could do the same for linux. I can't remember the exact command though, but it must be possible.
I think grub uses something like this (at least, for my configuration, don't take this over litterary):
grub /boot/vmlinuz-2.6.10-5-386 root=/dev/hda3 ro quiet splash
Maybe you can take a look at google for the exact syntax.
Try to enter a similar command, it might work. Once you get into Suse, I believe, like you've mentioned, that you can repair the bootloader with Yast. All that needs to happen is to get Suse booting.